Cisco Security Advisory: Cisco IOS Virtual Private Dial-up Network Denial of Service Vulnerability



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Cisco Security Advisory: Cisco IOS Virtual Private Dial-up Network
Denial of Service Vulnerability

Advisory ID: cisco-sa-20080326-pptp

http://www.cisco.com/warp/public/707/cisco-sa-20080326-pptp.shtml

Revision 1.0

For Public Release 2008 March 26 1600 UTC (GMT)

Summary
=======

Two vulnerabilities exist in the virtual private dial-up network
(VPDN) solution when Point-to-Point Tunneling Protocol (PPTP) is used
in certain Cisco IOS releases prior to 12.3. PPTP is only one of the
supported tunneling protocols used to tunnel PPP frames within the
VPDN solution.

The first vulnerability is a memory leak that occurs as a result of
PPTP session termination. The second vulnerability may consume all
interface descriptor blocks on the affected device because those
devices will not reuse virtual access interfaces. If these
vulnerabilities are repeatedly exploited, the memory and/or interface
resources of the attacked device may be depleted.

Cisco has made free software available to address these vulnerabilities
for affected customers.

There are no workarounds available to mitigate the effects of these
vulnerabilities.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080326-pptp.shtml

Note: The March 26, 2008 publication includes five security
advisories. The advisories all address vulnerabilities in Cisco's
Internetwork Operating System (IOS) software. Each advisory lists the
releases that correct the vulnerability described in the advisory,
and also lists the releases that correct the vulnerabilities in the
other five advisories. Please reference the following software table
to find a release that fixes all published software advisories as of
March 26th, 2008:

* March 26th Bundled IOS Advisory Table
http://www.cisco.com/warp/public/707/cisco-sa-20080326-bundle.shtml

Individual publication links are listed below:

* Cisco IOS Virtual Private Dial-up Network Denial of Service
Vulnerability
http://www.cisco.com/warp/public/707/cisco-sa-20080326-pptp.shtml

* Multiple DLSw Denial of Service Vulnerabilities in Cisco IOS
http://www.cisco.com/warp/public/707/cisco-sa-20080326-dlsw.shtml

* Cisco IOS User Datagram Protocol Delivery Issue For IPv4/IPv6
Dual-stack Routers
http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml

* Vulnerability in Cisco IOS with OSPF, MPLS VPN, and Supervisor
32, Supervisor 720, or Route Switch Processor 720
http://www.cisco.com/warp/public/707/cisco-sa-20080326-queue.shtml

* Cisco IOS Multicast Virtual Private Network (MVPN) Data Leak
http://www.cisco.com/warp/public/707/cisco-sa-20080326-mvpn.shtml


Affected Products
=================

Devices that are running certain Cisco IOS versions prior to 12.3
with VPDN enabled may be affected by these vulnerabilities.

Vulnerable Products
+------------------

Devices that are running affected versions of Cisco IOS with VPDN
enabled and are configured to accept termination of PPTP sessions are
vulnerable.

To determine whether VPDN is enabled on your device, log in to the
device and issue the command-line interface (CLI) command "show
running-config". If the output contains "vpdn enable" along with a
"vpdn-group <name>" command, VPDN is enabled on the device. The device
will accept termination of PPTP sessions if the command "protocol any"
or "protocol pptp" is defined under the "vpdn-group <name>" command.
The following example shows a device that is running VPDN and will
accept termination of PPTP sessions:

Router#show running-config
Building configuration...

!
!--- Output truncated.
!

vpdn enable

!

vpdn-group test_only
! Default PPTP VPDN group
accept-dialin
protocol pptp
virtual-template 1

!
!---Remaining output truncated.


To determine the software version running on a Cisco product, log in
to the device and issue the "show version" command to display the
system banner. Cisco IOS software will identify itself as
"Internetwork Operating System Software" or simply "IOS." On the next
line of output, the image name will be displayed between parentheses,
followed by "Version" and the IOS release name. Other Cisco devices
will not have the "show version" command or will give different output.

The following example identifies a Cisco product that is running
Cisco IOS release 12.2(7):

Cisco Internetwork Operating System Software
IOS (tm) 7200 Software (C7200-IS-M), Version 12.2(7), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Tue 15-Jan-02 18:31 by pwade
Image text-base: 0x600089C0, data-base: 0x613A6000

Additional information about Cisco IOS release naming can be found at
http://www.cisco.com/warp/public/620/1.html.

Products Confirmed Not Vulnerable
+--------------------------------

Devices that are running Cisco IOS versions 12.3 and later are not
affected by these vulnerabilities. Devices that are explicitly
configured for VPDN protocols other than PPTP are not affected.

Devices that are running Cisco IOS versions prior to 12.3 and do not
have VPDN enabled are not affected by these vulnerabilities.

Cisco IOS XR is not affected by these vulnerabilities.

Details
=======

VPDNs securely carry private data over a public network, allowing
remote users to access a private network over a shared infrastructure
such as the Internet. VPDNs maintain the same security and management
policies as a private network, while providing a cost-effective
method for point-to-point connections between remote users and a
central network.

PPTP is a network protocol that enables the secure transfer of data
from a remote client to a private enterprise server by creating a
VPDN across TCP/IP-based data networks. PPTP supports on-demand,
multiprotocol, virtual private networking over public networks, such
as the Internet.

Details regarding the two known vulnerabilities in Cisco IOS devices
that are running affected versions of system software follow:

* Memory Leak due to PPTP Session Termination

Upon completion of a PPTP session, memory is leaked from the
processor memory on the terminating device. This is shown in the
output of "show process memory" under the *Dead* process. The
*Dead* process is not a real process. Its function is to account
for the memory that is allocated under the context of another
process which has terminated, in this case PPTP. When the
administrator is logged into the device, if the device is under
exploitation, the Holding entry of the *Dead* process under the
"show process memory" command will be increasing. Following is
an example showing a device that is holding *Dead* memory:

Router#show process memory
Total: 199718560, Used: 11147828, Free: 188570732
PID TTY Allocated Freed Holding Getbufs Retbufs Process
0 0 99812 1848 8415816 0 0 *Init*
0 0 444 778840 444 0 0 *Sched*
0 0 17481700 4930848 819672 180908 0 *Dead*
1 0 284 284 3828 0 0 Load Meter

!--- Output truncated.

The CLI command "show memory dead" allows administrators to examine
the contents of *Dead*. The output will display many occurrences
of PPTP in the output if the PPTP process is causing the leak.
The following example shows the dead memory for a device that has
been exploited by the vulnerability

Router#show memory dead
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 6225FF40 224002240 11906736 212095504 212082872 212084464
I/O 20000000 33554440 994136 32560304 32560304 32560252
I/O-2 F800000 8388616 1020632 7367984 7367984 7367932


Processor memory

Address Bytes Prev Next Ref PrevF NextF Alloc PC what
62275DC8 0000000048 62275D68 62275E24 001 ------- ------- 60654230 PPTP create idb
62275E24 0000000052 62275DC8 62275E84 001 ------- ------- 60654230 PPTP create idb
62275E84 0000000052 62275E24 62275EE4 001 ------- ------- 60654230 PPTP create idb
....

!--- remaining output truncated.

This vulnerability is documented in Cisco bug ID CSCsj58566
and Common Vulnerabilities and Exposures (CVE) identifier
CVE-2008-1151 has been assigned to this vulnerability.

* Virtual Access Interfaces Are Not Re-used

Upon completion of a PPTP session, affected devices do not remove
the virtual access interface that is associated with the PPTP
session and do not reuse the interfaces in any future
connections.

This situation can result in an exhaustion of the interface
descriptor block (IDB) limit, which will prevent any new
interfaces being created within Cisco IOS, effectively blocking
all new VPDN connections, even though the router may still have
enough processor memory to remain up and running. A reload of the
device is required to remove the interfaces.

An IDB is a Cisco IOS internal data structure that contains
information such as the IP address, interface state, and packet
statistics. Cisco IOS software maintains one IDB for each
interface present on a platform and one IDB for each
subinterface.

Further documentation on Cisco IOS IDBs can be found at:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_tech_note09186a0080094322.shtml
This vulnerability is documented in Cisco bug ID CSCdv59309
and Common Vulnerabilities and Exposures (CVE) identifier
CVE-2008-1150 has been assigned to this vulnerability.

Vulnerability Scoring Details
=============================

Cisco is providing scores for the vulnerabilities in this advisory
based on the Common Vulnerability Scoring System (CVSS). The CVSS
scoring in this Security Advisory is done in accordance with CVSS
version 2.0.

Cisco will provide a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.

CVSS is a standards based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.

Cisco has provided an FAQ to answer additional questions regarding
CVSS at
http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to help compute the
environmental impact for individual networks at
http://intellishield.cisco.com/security/alertmanager/cvss

CSCsj58566 - Memory Leak due to PPTP Session Termination

CVSS Base Score - 7.1

Access Vector: Network
Access Complexity: Medium
Authentication: None

Confidentiality Impact: None
Integrity Impact: None
Availability Impact: Complete

CVSS Temporal Score - 5.9

Exploitability: Functional
Remediation Level: Official-Fix
Report Confidence: Confirmed

CSCdv59309 - Virtual Access Interfaces Are Not Re-used

CVSS Base Score - 4.3

Access Vector: Network
Access Complexity: Medium
Authentication: None

Confidentiality Impact: None
Integrity Impact: None
Availability Impact: Partial

CVSS Temporal Score - 3.6

Exploitability: Functional
Remediation Level: Official-Fix
Report Confidence: Confirmed

Impact
======

Successful exploitation of the vulnerability may result in a memory
leak of processor memory or consumption of all available IDBs on the
device. With continued exploitation, the device will deplete its
processor memory or reach an IDB limit. Both impacts would result in
a denial of service condition for the device.

Software Versions and Fixes
===========================

When considering software upgrades, also consult
http://www.cisco.com/go/psirt and any subsequent advisories to
determine exposure and a complete upgrade solution.

In all cases, customers should exercise caution to be certain the
devices to be upgraded contain sufficient memory and that current
hardware and software configurations will continue to be supported
properly by the new release. If the information is not clear, contact
the Cisco Technical Assistance Center ("TAC") or your contracted
maintenance provider for assistance.

Each row of the Cisco IOS software table (below) names a Cisco IOS
release train. If a given release train is vulnerable, then the
earliest possible releases that contain the fix (along with the
anticipated date of availability for each, if applicable) are listed
in the "First Fixed Release" column of the table. The "Recommended
Release" column indicates the releases which have fixes for all the
published vulnerabilities at the time of this Advisory. A device
running a release in the given train that is earlier than the release
in a specific column (less than the First Fixed Release) is known to
be vulnerable. Cisco recommends upgrading to a release equal to or
later than the release in the "Recommended Releases" column of the
table.

+----------------------------------------+
| Major | Availability of Repaired |
| Release | Releases |
|------------+---------------------------|
| Affected | First Fixed | Recommended |
| 12.0-Based | Release | Release |
| Releases | | |
|------------+-------------+-------------|
| 12.0 | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0DA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0DB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0DC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0S | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SP | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0ST | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0SZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0T | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0W | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0WC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0WT | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.0(7)XE2 | |
| | are | |
| 12.0XE | vulnerable, | |
| | release | |
| | 12.0(7)XE2 | |
| | and later | |
| | are not | |
| | vulnerable; | |
|------------+-------------+-------------|
| 12.0XF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XI | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XJ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XK | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XM | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XN | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XQ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XR | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XS | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XV | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.0XW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| Affected | First Fixed | Recommended |
| 12.1-Based | Release | Release |
| Releases | | |
|------------+-------------+-------------|
| 12.1 | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1AA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1AX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.1(22)AY1 | |
| | are | |
| 12.1AY | vulnerable, | 12.1(22) |
| | release | EA11 |
| | 12.1(22)AY1 | |
| | and later | |
| | are not | |
| | vulnerable; | |
|------------+-------------+-------------|
| 12.1AZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1CX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1DA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1DB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1DC | first fixed | 12.4(18a) |
| | in 12.2B | |
|------------+-------------+-------------|
| 12.1E | Vulnerable; | |
| | contact TAC | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.1(11)EA1 | |
| | are | |
| 12.1EA | vulnerable, | 12.1(22) |
| | release | EA11 |
| | 12.1(11)EA1 | |
| | and later | |
| | are not | |
| | vulnerable; | |
|------------+-------------+-------------|
| 12.1EB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1EC | first fixed | 12.3(23)BC1 |
| | in 12.2BC | |
|------------+-------------+-------------|
| 12.1EO | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1EU | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1EV | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1EW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1EX | Vulnerable; | |
| | contact TAC | |
|------------+-------------+-------------|
| 12.1EY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1EZ | Vulnerable; | |
| | contact TAC | |
|------------+-------------+-------------|
| 12.1GA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1GB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1T | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| 12.1XA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XI | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XJ | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.1XK | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XL | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XM | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.1XN | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XO | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XP | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XQ | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XR | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XS | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XT | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.1XU | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XV | first fixed | 12.3(26) |
| | in 12.2XB | |
|------------+-------------+-------------|
| 12.1XW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1XX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1XY | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| 12.1XZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YA | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YB | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YC | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YD | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.1(5)YE6 | |
| | are | |
| | vulnerable, | |
| 12.1YE | release | 12.3(26) |
| | 12.1(5)YE6 | |
| | and later | |
| | are not | |
| | vulnerable; | |
| | first fixed | |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YF | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.1YG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.1YH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.1YI | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.1YJ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| Affected | First Fixed | Recommended |
| 12.2-Based | Release | Release |
| Releases | | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2 | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| 12.2B | 12.2(4)B5 | 12.4(18a) |
|------------+-------------+-------------|
| | 12.2(15) | |
| | BC1e | |
| | | |
| 12.2BC | 12.2(15) | 12.3(23)BC1 |
| | BC2d | |
| | | |
| | 12.2(8)BC1 | |
|------------+-------------+-------------|
| | 12.2(4)BW1 | |
| 12.2BW | | 12.3(26) |
| | 12.2(4)BW1a | |
|------------+-------------+-------------|
| 12.2BY | 12.2(8)BY | 12.4(18a) |
|------------+-------------+-------------|
| 12.2BZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2CX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2CY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2CZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2DA | Vulnerable; | |
| | contact TAC | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2DD | first fixed | 12.4(18a) |
| | in 12.2B | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2DX | first fixed | 12.4(18a) |
| | in 12.2B | |
|------------+-------------+-------------|
| 12.2EU | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2EW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2EWA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2EX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2EY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2EZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2FX | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2FY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2FZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2IXA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2IXB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2IXC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2IXD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2IXE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2JA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2JK | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2MB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2MC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.2(18)S | |
| | are | |
| | vulnerable, | |
| | release | |
| 12.2S | 12.2(18)S | 12.2(25)S15 |
| | and later | |
| | are not | |
| | vulnerable; | |
| | migrate to | |
| | any release | |
| | in 12.2SRC | |
|------------+-------------+-------------|
| 12.2SB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SBC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SCA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SED | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SEG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SGA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SM | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SO | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SRA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SRB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SRC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2SU | migrate to | 12.4(18a) |
| | any release | |
| | in 12.3T | |
|------------+-------------+-------------|
| 12.2SV | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SVA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SVC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SVD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Releases | |
| | prior to | |
| | 12.2(17a)SX | |
| | are | |
| | vulnerable, | |
| | release | 12.2(18) |
| 12.2SX | 12.2(17a)SX | SXF13 |
| | and later | |
| | are not | |
| | vulnerable; | |
| | migrate to | |
| | any release | |
| | in 12.2SXF | |
|------------+-------------+-------------|
| 12.2SXA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SXB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SXD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SXE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SXF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2SXH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2SY | migrate to | 12.2(18) |
| | any release | SXF13 |
| | in 12.2SXB | |
|------------+-------------+-------------|
| | | 12.2(25)S15 |
| | Vulnerable; | |
| 12.2SZ | migrate to | 12.2(28) |
| | any release | SB12 |
| | in 12.2SRC | |
| | | 12.2(33)SRC |
|------------+-------------+-------------|
| | 12.2(15)T4e | |
| 12.2T | | 12.3(26) |
| | 12.2(8)T | |
|------------+-------------+-------------|
| 12.2TPC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2UZ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XA | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.2XB | 12.2(2)XB5 | 12.3(26) |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XC | migrate to | 12.4(18a) |
| | any release | |
| | in 12.3T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XD | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XE | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XF | first fixed | 12.3(23)BC1 |
| | in 12.2BC | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XG | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XH | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XI | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XJ | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XK | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.2XL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2XM | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2XN | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2XO | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XQ | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.2XR | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XS | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XT | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XU | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2XV | migrate to | 12.3(26) |
| | any release | |
| | in 12.3 | |
|------------+-------------+-------------|
| 12.2XW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YA | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2YC | first fixed | 12.3(26) |
| | in 12.2T | |
|------------+-------------+-------------|
| 12.2YD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | | 12.2(25)S15 |
| | Vulnerable; | |
| 12.2YE | migrate to | 12.2(28) |
| | any release | SB12 |
| | in 12.2SRC | |
| | | 12.2(33)SRC |
|------------+-------------+-------------|
| 12.2YF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YJ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YK | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YM | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YN | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2YO | migrate to | 12.2(18) |
| | any release | SXF13 |
| | in 12.2SXB | |
|------------+-------------+-------------|
| 12.2YP | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YQ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YR | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YS | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YT | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YU | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YV | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2YW | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2YX | migrate to | 12.4(18a) |
| | any release | |
| | in 12.3T | |
|------------+-------------+-------------|
| 12.2YY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| | | 12.2(25)S15 |
| | Vulnerable; | |
| 12.2YZ | migrate to | 12.2(28) |
| | any release | SB12 |
| | in 12.2SRC | |
| | | 12.2(33)SRC |
|------------+-------------+-------------|
| | Vulnerable; | |
| 12.2ZA | migrate to | 12.2(18) |
| | any release | SXF13 |
| | in 12.2SXB | |
|------------+-------------+-------------|
| 12.2ZB | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZC | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZD | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZE | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZF | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZG | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZH | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZJ | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZL | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZP | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZU | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| 12.2ZY | Not | |
| | Vulnerable | |
|------------+-------------+-------------|
| Affected | First Fixed | Recommended |
| 12.3-Based | Release | Release |
| Releases | | |
|----------------------------------------|
| There are no affected 12.3 based |
| releases |
|----------------------------------------|
| Affected | First Fixed | Recommended |
| 12.4-Based | Release | Release |
| Releases | | |
|----------------------------------------|
| There are no affected 12.4 based |
| releases |
+----------------------------------------+

Workarounds
===========

There are no workarounds for this vulnerability. Cisco recommends
upgrading to the fixed version of Cisco IOS.

Obtaining Fixed Software
========================

Cisco will make free software available to address this vulnerability
for affected customers. This advisory will be updated as fixed
software becomes available. Prior to deploying software, customers
should consult their maintenance provider or check the software for
feature set compatibility and known issues specific to their
environment.

Customers may only install and expect support for the feature sets
they have purchased. By installing, downloading, accessing or
otherwise using such software upgrades, customers agree to be bound
by the terms of Cisco's software license terms found at
http://www.cisco.com/public/sw-license-agreement.html
or as otherwise set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact either "psirt@xxxxxxxxx" or "security-alert@xxxxxxxxx"
for software upgrades.

Customers with Service Contracts
+-------------------------------

Customers with contracts should obtain upgraded software through
their regular update channels. For most customers, this means that
upgrades should be obtained through the Software Center on Cisco's
worldwide website at http://www.cisco.com.

Customers using Third Party Support Organizations
+------------------------------------------------

Customers whose Cisco products are provided or maintained through
prior or existing agreement with third-party support organizations
such as Cisco Partners, authorized resellers, or service providers
should contact that support organization for guidance and assistance
with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific
customer situations such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied workaround or
fix is the most appropriate for use in the intended network before it
is deployed.

Customers without Service Contracts
+----------------------------------

Customers who purchase direct from Cisco but who do not hold a Cisco
service contract and customers who purchase through third-party
vendors but are unsuccessful at obtaining fixed software through
their point of sale should get their upgrades by contacting the Cisco
Technical Assistance Center (TAC). TAC contacts are as follows.

* +1 800 553 2447 (toll free from within North America)
* +1 408 526 7209 (toll call from anywhere in the world)
* e-mail: tac@xxxxxxxxx

Have your product serial number available and give the URL of this
notice as evidence of your entitlement to a free upgrade. Free
upgrades for non-contract customers must be requested through the
TAC.

Refer to http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
for additional TAC contact information, including special localized
telephone numbers and instructions and e-mail addresses for use in
various languages.

Exploitation and Public Announcements
=====================================

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.

We would like to thank Martin Kluge of Elxsi Security for reporting
these vulnerabilities to us. We greatly appreciate the opportunity to
work with researchers on security vulnerabilities, and welcome the
opportunity to review and assist with security vulnerability reports
against Cisco products.

Status of this Notice: FINAL
============================

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY
KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE
INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS
AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS
DOCUMENT AT ANY TIME.

A stand-alone copy or Paraphrase of the text of this document that
omits the distribution URL in the following section is an
uncontrolled copy, and may lack important information or contain
factual errors.

Distribution
============

This advisory is posted on Cisco's worldwide website at :

http://www.cisco.com/warp/public/707/cisco-sa-20080206-pptp.shtml

In addition to worldwide web posting, a text version of this notice
is clear-signed with the Cisco PSIRT PGP key and is posted to the
following e-mail and Usenet news recipients.

* cust-security-announce@xxxxxxxxx
* first-teams@xxxxxxxxx
* bugtraq@xxxxxxxxxxxxxxxxx
* vulnwatch@xxxxxxxxxxxxx
* cisco@xxxxxxxxxxxxxxxxx
* cisco-nsp@xxxxxxxxxxxxxxx
* full-disclosure@xxxxxxxxxxxxxxxxx
* comp.dcom.sys.cisco@xxxxxxxxxxxxxxxxxx

Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on
mailing lists or newsgroups. Users concerned about this problem are
encouraged to check the above URL for any updates.

Revision History
================

+---------------------------------------+
| Revision | | Initial |
| 1.0 | 2008-March-26 | public |
| | | release |
+---------------------------------------+

Cisco Security Procedures
=========================

Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and
registering to receive security information from Cisco, is available
on Cisco's worldwide website at
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
This includes instructions for press inquiries regarding Cisco
security notices. All Cisco security advisories are available at
http://www.cisco.com/go/psirt.
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