(Red Hat Issues Fix) QEMU Bug in 'ccid-card-passthru.c' Lets Local Users Gain Elevated Privileges or Deny Service
SecurityTracker Alert ID: 1026399|
SecurityTracker URL: http://securitytracker.com/id/1026399
(Links to External Site)
Date: Dec 9 2011
Denial of service via local system, User access via local system|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): prior to 1.0|
A vulnerability was reported in QEMU. A local user can obtain elevated privileges on the target system. A local user can cause denial of service conditions.|
When a CCID card passthru device is used, a local user can exploit a flaw in the processing of VSC_ATR messages to cause the QEMU process to crash. A local user may be able to exploit this to obtain elevated privileges.
The vulnerability resides in 'hw/ccid-card-passthru.c'.
A local user can obtain elevated privileges on the target system.|
A local user can cause denial of service conditions on the target system.
Red Hat has issued a fix.|
The Red Hat advisory is available at:
Vendor URL: wiki.qemu.org/ (Links to External Site)
Linux (Red Hat Enterprise)|
This archive entry is a follow-up to the message listed below.|
Source Message Contents
Date: Thu, 8 Dec 2011 21:28:09 +0000|
Subject: [RHSA-2011:1801-01] Important: qemu-kvm security update
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Red Hat Security Advisory
Synopsis: Important: qemu-kvm security update
Advisory ID: RHSA-2011:1801-01
Product: Red Hat Enterprise Linux
Advisory URL: https://rhn.redhat.com/errata/RHSA-2011-1801.html
Issue date: 2011-12-08
CVE Names: CVE-2011-4111
Updated qemu-kvm packages that fix one security issue are now available for
Red Hat Enterprise Linux 6.1 Extended Update Support.
The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link in the References section.
2. Relevant releases/architectures:
Red Hat Enterprise Linux Server EUS (v. 6.1) - x86_64
KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component
for running virtual machines using KVM.
A flaw was found in the way qemu-kvm handled VSC_ATR messages when a guest
was configured for a CCID (Chip/Smart Card Interface Devices) USB smart
card reader in passthrough mode. An attacker able to connect to the port on
the host being used for such a device could use this flaw to crash the
qemu-kvm process on the host or, possibly, escalate their privileges on the
All users of qemu-kvm should upgrade to these updated packages, which
contain a backported patch to resolve this issue. After installing this
update, shut down all running virtual machines. Once all virtual machines
have shut down, start them again for this update to take effect.
Before applying this update, make sure all previously-released errata
relevant to your system have been applied.
This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
5. Bugs fixed (http://bugzilla.redhat.com/):
751310 - CVE-2011-4111 qemu: ccid: buffer overflow in handling of VSC_ATR message
6. Package List:
Red Hat Enterprise Linux Server EUS (v. 6.1):
These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
The Red Hat security contact is <email@example.com>. More contact
details at https://access.redhat.com/security/team/contact/
Copyright 2011 Red Hat, Inc.
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