Bug 755640 (CVE-2011-4327) - CVE-2011-4327 openssh: Unauthorized local access to host keys on platforms where ssh-rand-helper used
Summary: CVE-2011-4327 openssh: Unauthorized local access to host keys on platforms wh...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2011-4327
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-11-21 16:53 UTC by Jan Lieskovsky
Modified: 2021-02-24 13:43 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-11-21 17:21:49 UTC
Embargoed:


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Description Jan Lieskovsky 2011-11-21 16:53:18 UTC
A security flaw was found in the way ssh-keysign, a ssh helper program for host based authentication, attempted to retrieve enough entropy information on configurations that lacked a built-in entropy pool in OpenSSL (a ssh-rand-helper program would be executed to retrieve the entropy from the system environment). A local attacker could use this flaw to obtain unauthorized access to host keys via ptrace(2) process trace attached to the 'ssh-rand-helper' program.

References:
[1] http://www.openssh.com/txt/release-5.8p2
[2] http://www.openssh.com/txt/portable-keysign-rand-helper.adv
[3] http://www.nessus.org/plugins/index.php?view=single&id=53841
[4] http://www.openwall.com/lists/oss-security/2011/11/21/11
    (CVE assignment)

Comment 1 Jan Lieskovsky 2011-11-21 17:06:08 UTC
This issue did NOT affect the versions of the openssh package, as shipped with Red Hat Enterprise Linux 4, 5, and 6, since these versions use a built-in entropy pool to generate and retrieve entropy information by performing host-based authentication.

--

This issue did NOT affect the versions of the openssh package, as shipped with Fedora release of 14, 15, and 16, since these versions use a built-in entropy pool to generate and retrieve entropy information by performing host-based authentication.

Comment 2 Jan Lieskovsky 2011-11-21 17:21:49 UTC
Statement:

Not vulnerable. This issue did not affect the versions of openssh as shipped with Red Hat Enterprise Linux 4, 5, and 6, as they use a built-in entropy pool to generate and retrieve entropy information when performing host-based authentication.


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