Bug 1287572 (CVE-2015-8313) - CVE-2015-8313 gnutls: First byte of the padding in CBC mode is not checked
Summary: CVE-2015-8313 gnutls: First byte of the padding in CBC mode is not checked
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2015-8313
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: 1287573
TreeView+ depends on / blocked
 
Reported: 2015-12-02 11:23 UTC by Adam Mariš
Modified: 2019-09-29 13:40 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-12-02 12:56:26 UTC
Embargoed:

Attachments (Terms of Use)
Patch extracted from Debian packages gnutls26-2.12.20-8+deb7u4 (764 bytes, text/plain)
2015-12-02 12:53 UTC, Tomas Hoger 		no flags Details
View All

Description Adam Mariš 2015-12-02 11:23:09 UTC 
It was discovered that gnutls incorrectly validates the first byte of padding in CBC modes. A remote attacker can possibly take advantage of this flaw to perform a padding oracle attack. Affected are older versions of gnutls (2.x).

Public via:

https://www.debian.org/security/2015/dsa-3408
http://seclists.org/bugtraq/2015/Dec/0
Comment 1 Nikos Mavrogiannopoulos 2015-12-02 12:02:27 UTC 
This bug does not affect RHEL-6 or RHEL-7. They have been patched with the proper fixes for Lucky13 which included the fix for that issue.
Comment 2 Nikos Mavrogiannopoulos 2015-12-02 12:04:21 UTC 
It doesn't affect RHEL-5 either.
Comment 3 Tomas Hoger 2015-12-02 12:49:59 UTC 
Details of this issue can be found in the Hanno Böck's blog post:

https://blog.hboeck.de/archives/877-A-little-POODLE-left-in-GnuTLS-old-versions.html

Here is also the original Ubuntu bug report:

https://bugs.launchpad.net/ubuntu/+source/gnutls26/+bug/1510163
Comment 4 Tomas Hoger 2015-12-02 12:53:10 UTC 
Created attachment 1101466 [details]
Patch extracted from Debian packages gnutls26-2.12.20-8+deb7u4
Comment 5 Tomas Hoger 2015-12-02 12:56:26 UTC 
The GnuTLS version of Lucky13 got CVE-2013-1619 (bug 908238) and got corrected in Red Hat Enterprise Linux 5 and 6.  As noted above, the fix used addressed Lucky13 without leaving this small problem in.
Note You need to log in before you can comment on or make changes to this bug.