Bug 800655 (CVE-2012-0920)

Summary:	CVE-2012-0920 dropbear: use-after-free vulnerability
Product:	[Other] Security Response	Reporter:	Vincent Danen <vdanen>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	buytenh, gwync, itamar, jrusnack
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
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Clone Of:		Environment:
Last Closed:	2012-08-03 17:27:22 UTC	Type:	---
Regression:	---	Mount Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	800656, 800657
Bug Blocks:

Description Vincent Danen 2012-03-06 21:20:32 UTC

It was reported [1] that the Dropbear SSH server suffered from a use-after-free flaw in how the server managed channels concurrency.  A specially-crafted request could trigger a use-after-free condition which could then be used to potentially execute arbitrary code with root privileges, provided that the user has been authenticated using a public key and also that a command restriction is enforced (the "command" option must be used in the authorized_keys file).

This has been corrected upstream in version 2012.55 [2] and is reported to affect versions 0.52 through 2011.54.

[1] http://archives.neohapsis.com/archives/fulldisclosure/2012-02/0404.html
[2] https://secure.ucc.asn.au/hg/dropbear/rev/818108bf7749

Comment 1 Vincent Danen 2012-03-06 21:36:39 UTC

Tracking bugs were filed for:

Fedora-all: bug #800656
EPEL-6: bug #800657

Comment 2 Vincent Danen 2012-08-03 17:27:22 UTC

dropbear-0.55-1 has been pushed to all supported versions of Fedora and EPEL:

http://koji.fedoraproject.org/koji/packageinfo?packageID=5596