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TITLE:
Xen DMA Requests IOMMU Denial of Service Weakness

SECUNIA ADVISORY ID:
SA45622

VERIFY ADVISORY:
Secunia.com
http://secunia.com/advisories/45622/
Customer Area (Credentials Required)
https://ca.secunia.com/?page=viewadvisory&vuln_id=45622

RELEASE DATE:
2011-08-16

DISCUSS ADVISORY:
http://secunia.com/advisories/45622/#comments

AVAILABLE ON SITE AND IN CUSTOMER AREA:
 * Last Update
 * Popularity
 * Comments
 * Criticality Level
 * Impact
 * Where
 * Solution Status
 * Operating System / Software
 * CVE Reference(s)

http://secunia.com/advisories/45622/

ONLY AVAILABLE IN CUSTOMER AREA:
 * Authentication Level
 * Report Reliability
 * Secunia PoC
 * Secunia Analysis
 * Systems Affected
 * Approve Distribution
 * Remediation Status
 * Secunia CVSS Score
 * CVSS

https://ca.secunia.com/?page=viewadvisory&vuln_id=45622

ONLY AVAILABLE WITH SECUNIA CSI AND SECUNIA PSI:
 * AUTOMATED SCANNING

http://secunia.com/vulnerability_scanning/personal/
http://secunia.com/vulnerability_scanning/corporate/wsus_sccm_3rd_third_party_patching/

DESCRIPTION:
A weakness has been reported in Xen, which can be exploited by
malicious, local users in a guest virtual machine to cause a DoS
(Denial of Service).

The weakness is caused due to Xen not properly restricting bogus DMA
requests to PCI/PCIE devices under direct control by the virtual
machine, which can be exploited to cause IOMMU faults and a high CPU
load or deadlock.

The weakness is reported in version 4.1.1. Other versions may also be
affected.

SOLUTION:
Fixed in the Mercurial repository.

PROVIDED AND/OR DISCOVERED BY:
Reported by the vendor.

ORIGINAL ADVISORY:
http://lists.xensource.com/archives/html/xen-devel/2011-06/msg01106.html
http://xenbits.xen.org/hg/staging/xen-4.1-testing.hg/rev/84e3706df07a

OTHER REFERENCES:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

DEEP LINKS:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED DESCRIPTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED SOLUTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXPLOIT:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

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About:
This Advisory was delivered by Secunia as a free service to help
private users keeping their systems up to date against the latest
vulnerabilities.

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Please Note:
Secunia recommends that you verify all advisories you receive by
clicking the link.
Secunia NEVER sends attached files with advisories.
Secunia does not advise people to install third party patches, only
use those supplied by the vendor.

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