Gentoo: cyrus-sasl buffer overflow vulnerability
Posted by LinuxSecurity.com Team   
Gentoo Insufficient buffer length checking in user name canonicalization may allow attacker to execute arbitrary code on servers using Cyrus SASL library.

- --------------------------------------------------------------------
GENTOO LINUX SECURITY ANNOUNCEMENT 200212-10
- --------------------------------------------------------------------

PACKAGE : cyrus-sasl
SUMMARY : buffer overflows
DATE    : 2002-12-27 22:12 UTC
EXPLOIT : remote

- --------------------------------------------------------------------

From advisory:

"Insufficient buffer length checking in user name canonicalization
may allow attacker to execute arbitrary code on servers using Cyrus
SASL library. Client side library also has the bug but since the user
name is asked from the local user, there's probably not many
applications that care about it, except maybe webmails and the like.
This overflow only happens if default realm is set."

"LDAP authentication with saslauthd doesn't allocate enough memory
when it needs to escape characters '*', '(', ')', '\' and '\0' in
username and realm. This should be easily exploited with glibc's
malloc implementation."

"Log writer might not have allocated memory for the trailing \0 in
message. Probably hard to exploit, although you can affect the
logging data with at least anonymous authentication."

Read the full advisory at 
http://marc.theaimsgroup.com/?l=bugtraq&m=103946297703402&w=2

SOLUTION

It is recommended that all Gentoo Linux users who are running
dev-libs/cyrus-sasl-2.1.9 update their systems as follows:

emerge rsync
emerge cyrus-sasl
emerge clean

- --------------------------------------------------------------------
aliz@gentoo.org - GnuPG key is available at www.gentoo.org/~aliz
raker@gentoo.org
- --------------------------------------------------------------------