Xen set_debugreg denial of service

xen-setdebugreg-dos (78265) The risk level is classified as MediumMedium Risk

Description:

Xen is vulnerable to a denial of service, caused by an error when handling writes to the DR7 debug control register. A local attacker on a guest operating system could exploit this vulnerability to cause the host operating system to crash.

*CVSS:

Base Score: 2.1
  Access Vector: Local
  Access Complexity: Low
  Authentication: None
  Confidentiality Impact: None
  Integrity Impact: None
  Availability Impact: Partial
 
Temporal Score: 1.6
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed

Consequences:

Denial of Service

Remedy:

Refer to Xen Security Advisory 12 (CVE-2012-3494) for patch, upgrade or suggested workaround information. See References.

For other distributions:
Apply the appropriate update for your system. See References.

References:

  • CTX134708: Citrix XenServer Multiple Security Updates.
  • CTX134876: Citrix NetScaler SDX Multiple Security Updates .
  • Red Hat Bugzilla Bug 851139 Red Hat Bugzilla Bug 851139: CVE-2012-3494 kernel: xen: hypercall set_debugreg vulnerability.
  • Xen Security Advisory 12 (CVE-2012-3494): hypercall set_debugreg vulnerability.
  • BID-55400: Xen 'set_debugreg' CVE-2012-3494 Denial of Service Vulnerability
  • CVE-2012-3494: The set_debugreg hypercall in include/asm-x86/debugreg.h in Xen 4.0, 4.1, and 4.2, and Citrix XenServer 6.0.2 and earlier, when running on x86-64 systems, allows local OS guest users to cause a denial of service (host crash) by writing to the reserved bits of the DR7 debug control register.
  • DSA-2544: xen -- denial of service
  • OSVDB ID: 85197: Xen DR7 Debug Control Register Write Handling set_debugreg Hypercall Parsing Local DoS
  • SA50472: Xen Multiple Denial of Service and Privilege Escalation Vulnerabilities
  • SA50530: Citrix XenServer Denial of Service and Privilege Escalation Vulnerabilities

Platforms Affected:

  • Citrix NetScaler SDX 10.x
  • Citrix NetScaler SDX 9.x
  • Citrix XenServer 5.0
  • Citrix XenServer 5.5
  • Citrix XenServer 5.6
  • Citrix XenServer 6.0
  • XenSource Xen 4.1
  • XenSource Xen 4.1.1
  • XenSource Xen 4.1.2

Reported:

Sep 05, 2012

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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