[UNIX] Samba smbd Memory Exhaustion DoS

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Samba smbd Memory Exhaustion DoS


"The <http://www.samba.org/> smbd daemon maintains internal data
structures used track active connections to file and printer shares."

smbd may allow internal structures maintaining state for share connections
to grow unbounded.


Vulnerable Systems:
* Samba version 3.0.1 and above
* Samba version 3.0.22 and prior

In certain circumstances an attacker may be able to continually increase
the memory usage of an smbd process by issuing a large number of share
connection requests. This defect affects all Samba configurations.

CVE Information:

Vendor Status:
The vendor has issued a patch:
Index: source/smbd/service.c
--- source/smbd/service.c (revision 16676)
+++ source/smbd/service.c (working copy)
@@ -763,6 +763,11 @@
smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");

+ if (conn_num_open() > 2047) {
+ return NULL;
+ }
if(lp_security() != SEC_SHARE) {
vuser = get_valid_user_struct(vuid);
if (!vuser) {


The information has been provided by <mailto:jerry@xxxxxxxxx> Gerald
(Jerry) Carter.
The original article can be found at:
The patch can be downloaded at:
<http://us4.samba.org/samba/ftp/patches/security/samba-3.0-CAN-2006-3403.patch> http://us4.samba.org/samba/ftp/patches/security/samba-3.0-CAN-2006-3403.patch


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