Quick answers
- Is CVE-2015-8972 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2015-8972 being exploited in the wild.
- How severe is CVE-2015-8972?
- Critical severity, with a CVSS score of 9.8, published 23 January 2017.
- Which products and versions are affected?
- GNU GNU Chess before 6.2.4.
- Is there a fix for CVE-2015-8972?
- A patch was published on 2016-09-20: Fix committed to Savannah SVN repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2015-8972 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2015-8972?
- Check whether you run Gnu Chess. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A stack-based buffer overflow exists in the ValidateMove function within frontend/move.cc of GNU Chess (gnuchess). The vulnerability is caused by insufficient bounds checking when copying user-supplied move strings into a fixed-size buffer (MAXSTR, typically 128 bytes). While gnuchess is often used locally, the vulnerability can be exploited remotely if the engine is running in Universal Chess Interface (UCI) mode as a backend for a network-accessible service. An attacker providing a move string longer than the buffer can overwrite the stack, leading to a denial of service (crash) or arbitrary code execution. The issue was addressed in version 6.2.4 by adding a length check and null-terminating long inputs.
Affected products
- GNU GNU Chess before 6.2.4
Timeline
- 2015-10-29: disclosed: Initial bug report by Antti Karjalainen on the bug-gnu-chess mailing list
- 2016-09-20: patched: Fix committed to Savannah SVN repository
- 2016-11-14: advisory: CVE-2015-8972 assigned via oss-security mailing list
- 2017-01-23: other: NVD publication date
References
- http://lists.gnu.org/archive/html/bug-gnu-chess/2015-10/msg00002.html
- http://svn.savannah.gnu.org/viewvc/chess?revision=134&view=revision
- http://www.openwall.com/lists/oss-security/2016/11/13/2
- http://www.openwall.com/lists/oss-security/2016/11/14/11
- http://www.openwall.com/lists/oss-security/2016/11/14/12