Multiple vulnerabilities have been reported in CVS, which can be exploited by malicious users to cause a DoS (Denial of Service) or compromise a vulnerable system.

1) An NULL-termination error within the patch for the previous "Entry" line heap-based buffer overflow vulnerability can potentially be exploited to crash a vulnerable server.

2) A "double free" error can reportedly be exploited via the "Argumentx" command to execute arbitrary code on a vulnerable system.

3) A format string error within the processing of the CVS wrapper file can potentially be exploited to execute arbitrary code on a vulnerable system by including a specially crafted line containing format specifiers. However, successful exploitation requires CVSROOT commit access.

4) An integer overflow within the handling of the "Max-dotdot" CVS protocol command can be exploited to crash the CVS server and consume available disk space.

5) An boundary error within the "serve_notify()" function when handling empty data lines can potentially be exploited to execute arbitrary code.

6) Some underflow errors exist when reading configuration files containing empty lines from CVSROOT. Successful exploitation requires CVSROOT commit access, and the impact is unknown.

7) Various integer multiplication overflows may potentially be exploited for arbitrary code execution.

Solution
The vulnerabilities have been fixed in CVS Feature Version 1.12.9 and CVS Stable Version 1.11.17.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Derek Price
2-4) Stefan Esser, e-matters.
5-7) Sebastian Krahmer

Original Advisory
http://security.e-matters.de/advisories/092004.html

Other references
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers