Bug 1379302 (CVE-2016-6309) - CVE-2016-6309 openssl: Use After Free for large message sizes
Summary: CVE-2016-6309 openssl: Use After Free for large message sizes
Status: CLOSED NOTABUG
Alias: CVE-2016-6309
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
urgent
urgent
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=critical,public=20160926,repor...
Keywords: Security
Depends On:
Blocks: 1367347
TreeView+ depends on / blocked
 
Reported: 2016-09-26 10:33 UTC by Tomas Hoger
Modified: 2019-06-08 21:28 UTC (History)
33 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2016-09-26 10:36:59 UTC


Attachments (Terms of Use)


External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Knowledge Base (Solution) 2662211 None None None 2016-09-28 00:42 UTC

Description Tomas Hoger 2016-09-26 10:33:03 UTC
Quoting form the OpenSSL upstream advisory:


Fix Use After Free for large message sizes (CVE-2016-6309)
==========================================================

Severity: Critical

This issue only affects OpenSSL 1.1.0a, released on 22nd September 2016.

The patch applied to address CVE-2016-6307 resulted in an issue where if a
message larger than approx 16k is received then the underlying buffer to store
the incoming message is reallocated and moved. Unfortunately a dangling pointer
to the old location is left which results in an attempt to write to the
previously freed location. This is likely to result in a crash, however it
could potentially lead to execution of arbitrary code.

OpenSSL 1.1.0 users should upgrade to 1.1.0b

This issue was reported to OpenSSL on 23rd September 2016 by Robert
Święcki (Google Security Team), and was found using honggfuzz. The fix
was developed by Matt Caswell of the OpenSSL development team.


External References:

https://www.openssl.org/news/secadv/20160926.txt

Comment 1 Tomas Hoger 2016-09-26 10:36:59 UTC
The CVE-2016-6307 is tracked via bug 1378203.

Upstream commit:

https://git.openssl.org/?p=openssl.git;a=commitdiff;h=acacbfa7565c78d2273c0b2a2e5e803f44afefeb

The following commit seems to add test for this issue into upstream test suite:

https://git.openssl.org/?p=openssl.git;a=commitdiff;h=f8644220a05f75d51bbde627077cdf336e4d4592


Statement:

This issue did not affect any Red Hat product as they do not yet include OpenSSL 1.1.0.


Note You need to log in before you can comment on or make changes to this bug.