[Full-Disclosure] Heap Overflow in Oracle 9iAS / 10g Application Server Web Cache
From: Ioannis Migadakis (jmig_at_mail.gr)
To: firstname.lastname@example.org Date: Thu, 08 Apr 2004 14:50:42 EET('binary' encoding is not supported, stored as-is)
Advisory Name: Heap Overflow in Oracle 9iAS / 10g Application Server
Release Date: 8 April 2004
Application: Oracle Web Cache - all versions except 18.104.22.168.0 for
Windows, AIX & Tru64 which already contain fixes
Platform: All Oracle supported platforms -
Severity: Critical - Remote Code Execution
Category: Heap Overflow
Author: Ioannis Migadakis [email@example.com]
Vendor Status: Oracle has released Security Alert #66 and
patches are available for supported products.
CVE Candidate: CAN-2004-0385
About Web Cache
From Oracle's Web Site
"Oracle Web Cache is the software industry's leading application
acceleration solution. Designed for enterprise grid computing, OracleAS
Web Cache leverages state-of-the-art caching and compression
technologies to optimize application performance and more efficiently
utilize low-cost, existing hardware resources."
From Oracle's 9iAS Web Cache - Technical FAQ
"An integrated component of Oracle's application server infrastructure,
Oracle9iAS Web Cache is an innovative content delivery solution
designed to accelerate dynamic Web-based applications and reduce
From Oracle's Security Alert #66 Rev.1
"...a typical Core or Mid-Tier default installation of Oracle
Application Server includes Web Cache."
A heap overflow vulnerability exists in Oracle Web Cache - all
platforms. The vulnerability can be exploited remotely and the attacker
can execute code of his choice. Some firewalls may not protect against
this vulnerability. Patches are available from Oracle's Web Site and
should be applied immediately. The risk to exposure is high.
Web Cache application processes HTTP/HTTPS requests from clients and
passes them to Oracle HTTP Server(s).
HTTP/HTTPS ------------- -------------
client ----------> - Web Cache - -----> -HTTP Server-
Request ------------- -------------
By default Web Cache listens for incoming connections on port 7777 for
HTTP and 4443 for HTTPS. These ports are configured by the
administrator of the system and in real world installations they become
the well known ports 80 and 443 and they are available through the
firewall to all.
A heap overflow condition exists in "webcached" process when an invalid
HTTP/HTTPS request is made. The overflow can be triggered by sending an
overly long header as the HTTP Request Method. From RFC 2616 valid
values for the HTTP Request Method are GET, HEAD, POST, PUT, DELETE,
By supplying an HTTP Request Method header of 432 bytes long against
a Windows based Web Cache installation the following exception is
caused within ntdll.RtlAllocateHeap.
77FCBF00 MOV DWORD PTR DS:[ESI], ECX
77FCBF02 MOV DWORD PTR DS:[ECX+4], ESI
ECX and ESI are overwritten with the attacker supplied values. By
controlling the values of the registers ECX and ESI, it is possible to
write an arbitrary dword to any address. It all comes to the WHERE -
WHAT situation described in many security related documents. Also the
buffer is quite large - Oracle9iAS Web Cache uses 4 KB for the HTTP
headers as default buffer size. Using different variations of the exploit
technique it is possible to overwrite different CPU registers.
The vulnerability exists in all Oracle supported platforms. On Windows
the Web Cache is running under the Security Context of Local SYSTEM
account and in a successful exploitation of the vulnerability, a full
remote system compromise is possible. On Unix & Linux the Web Cache
process normally is running as user ORACLE and in a successful
exploitation of the vulnerability a complete compromise of the data
may be possible.
CERT has assigned VU#643985 for this vulnerability.
HTTP/HTTPS Method Heap Overflow & Firewalls
This vulnerability can bypass a large number of firewalls, so a
firewall can not be considered as a measure for protection against this
If the firewall uses Statefull Packet Inspection / Packet filtering and
operates in layers 3 & 4 (e.g. it can understand the difference between
port 80 and 21 but not between HTTP GET and HTTP POST) then this
firewall does not offer any protection against this vulnerability.
If the firewall uses some proxy features operating in the -so called-
"application" layer (7) (e.g. it can understand the difference between
HTTP GET and HTTP POST) then this firewall does offer protection
against this vulnerability.
The above are true for HTTP where a large number of HTTP proxies /
firewalls exists. Unfortunately for HTTPS the majority of the firewalls
do not offer protection against this vulnerability since HTTPS is
nothing more to them than TCP port 443.
After all, Oracle in Security Alert #66 correctly says "Firewalls
deployed within a corporate Intranet or between a corporate Intranet
and the Internet do not protect against these vulnerabilities."
Discovery: Ioannis Migadakis a.k.a. JMIG
17 April 2003 Vulnerability Discovered
22 April 2003 Contacted CERT
23 April 2003 Contacted Oracle
23 April 2003 CERT Replied - Assign VU#643985
12 March 2004 Oracle Security Alert #66 Rev.1 Released
2 April 2004 Oracle Security Alert #66 Rev.2 Released with Credits
8 April 2004 Public Advisory Released to
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