Bug 824919 (CVE-2012-2652) - CVE-2012-2652 qemu: vulnerable to temporary file symlink attacks
Summary: CVE-2012-2652 qemu: vulnerable to temporary file symlink attacks
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2012-2652
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: impact=moderate,public=20120528,repor...
Depends On: 825686 825687 825690 825691 825697
Blocks: 824924
TreeView+ depends on / blocked
 
Reported: 2012-05-24 15:35 UTC by Vincent Danen
Modified: 2019-06-08 19:08 UTC (History)
19 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-08-24 13:31:40 UTC


Attachments (Terms of Use)

Description Vincent Danen 2012-05-24 15:35:39 UTC
A flaw was found in how qemu, in snapshot mode (-snapshot command line argument), handled the creation and opening of the temporary file used to store the difference of the virtualized guest's read-only image and the current state.  In snapshot mode, bdrv_open() creates an empty temporary file without checking for any mkstemp() or close() failures; it also ignores the possibility of a buffer overrun given an exceptionally long $TMPDIR.  Because qemu re-opens that file after creation, it is possible to race qemu and insert a symbolic link with the same expected name as the temporary file, pointing to an attacker-chosen file.  This can be used to either overwrite the destination file with the privileges of the user running qemu (typically root), or to point to an attacker-readable file that could expose data from the guest to the attacker.

This flaw has been assigned the name CVE-2012-2652.

Comment 1 Jim Meyering 2012-05-28 07:32:05 UTC
To accommodate the imminent release of qemu-1.1,
I've posted the report and patch on the upstream mailing list:

  http://marc.info/?l=qemu-devel&m=133819025731504&w=2

Comment 5 Petr Matousek 2012-05-28 08:55:15 UTC
Created qemu tracking bugs for this issue

Affects: fedora-all [bug 825697]

Comment 9 Fedora Update System 2012-08-09 22:59:55 UTC
qemu-0.15.1-7.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 Fedora Update System 2012-08-09 23:02:02 UTC
qemu-1.0.1-1.fc17 has been pushed to the Fedora 17 stable repository.  If problems still persist, please make note of it in this bug report.


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