Bug 481376 (CVE-2008-5714)

Summary: CVE-2008-5714 qemu: off-by-one error in monitor.c causing VNC passwords to be truncated after 7th character
Product: [Other] Security Response Reporter: Josh Bressers <bressers>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: berrange, clalance, dwmw2, gcosta, markmc, sundaram, virt-maint, xen-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
URL: http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-5714
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-03-29 10:50:31 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Josh Bressers 2009-01-23 20:12:36 UTC
Off-by-one error in monitor.c in Qemu 0.9.1 might make it easier for remote attackers to guess the VNC password, which is limited to seven characters where eight was intended.


Comment 1 Tomas Hoger 2009-01-26 10:59:21 UTC
More information on setting VNC passwords for Qemu/KVM guests can be found here:

Looking at various version of Qemu, KVM and Xen shipped, following seem to be affected:

- Qemu - All versions shipped in stable Fedora versions are currently based on upstream version 0.9.1 that contains this flaw.

- KVM - Current versions in stable Fedora versions (65-15.fc9 and 74-10.fc10) contain this problem as well.  Issue was fixed in KVM upstream git report via:
and the fix is included in version 82 and later.

- Xen - Version of Xen as shipped in Red Hat Enterprise Linux 5 (3.0.3-80.el5) and Fedora 9 (3.2.0-15.fc9) are not affected by this flaw (longer (256) buffer used, full buffer size passed to monitor_readline()).  The flaw exists in Fedora 10 and Rawhide Xen versions (3.3.0-1.fc10 and 3.3.1-2.fc11, ioemu-qemu-xen).

Is there any way to run Qemu / KVM with monitor enabled when used with libvirt?  From the search through the XML format spec, there does not seem to be any option to enable it.  Is there a way to enable monitor in qemu-dm used by Xen?

Comment 2 Glauber Costa 2009-01-26 11:39:27 UTC
Oh god, will those CVEs on vnc ever stop?