Bug 1322264 (CVE-2016-3630)

Summary:	CVE-2016-3630 mercurial: remote code execution in binary delta decoding
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	mads, ndbecker2, pstodulk
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	mercurial 3.7.3	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-04-13 21:26:48 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1322268
Bug Blocks:	1322269

Description Andrej Nemec 2016-03-30 07:33:17 UTC

Mercurial prior to 3.7.3 contained two bounds-checking errors in its binary delta decoder that may be exploitable via clone, push, or pull.

External references:

https://www.mercurial-scm.org/wiki/WhatsNew#Mercurial_3.7.3_.282016-3-29.29

Upstream fixes:

https://selenic.com/repo/hg-stable/rev/b6ed2505d6cf
https://selenic.com/repo/hg-stable/rev/b9714d958e89

Comment 1 Andrej Nemec 2016-03-30 07:43:33 UTC

Created mercurial tracking bugs for this issue:

Affects: fedora-all [bug 1322268]

Comment 2 Fedora Update System 2016-04-07 15:48:03 UTC

mercurial-3.5.2-1.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 3 Fedora Update System 2016-04-07 15:50:25 UTC

mercurial-3.5.2-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Tomas Hoger 2016-04-13 21:26:48 UTC

There are two problems in the decode() function, each addressed by one of the patches above:

- frag list array l may be allocated to size that is 1 less than the number of items that will be written to
- negative frag data length values are not handled correctly, leading to incorrect update of pointer to the parsed data buffer

Both of these issue lead to buffer overflow.

These problems were introduced in this commit:

https://selenic.com/repo/hg-stable/rev/09e41ac6289d

The mercurial versions in Red Hat Enterprise Linux 6 and 7 do not include that change and hence are not affected by this issue.