Description
The physdev_get_free_pirq hypercall in arch/x86/physdev.c in Xen 4.1.x and Citrix XenServer 6.0.2 and earlier uses the return value of the get_free_pirq function as an array index without checking that the return value indicates an error, which allows guest OS users to cause a denial of service (invalid memory write and host crash) and possibly gain privileges via unspecified vectors.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | xen | 4.1.3-2 | — |
| Debian 13 | xen | 4.1.3-2 | — |
| Debian 12 | xen | 4.1.3-2 | — |
References
- 55082 third-party-advisory
- http://xenbits.xen.org/hg/xen-4.1-testing.hg/rev/6779ddca8593
- [Xen-announce] 20120905 Xen Security Advisory 13 (CVE-2012-3495) - hypercall physdev_get_free_pirq vulnerability mailing-list
- 51413 third-party-advisory
- GLSA-201309-24 vendor-advisory
- http://wiki.xen.org/wiki/Security_Announcements#XSA-13_hypercall_physdev_get_free_pirq_vulnerability
- openSUSE-SU-2012:1572 vendor-advisory
- 55406 vdb-entry
- 1027480 vdb-entry
- GLSA-201604-03 vendor-advisory
- SUSE-SU-2012:1132 vendor-advisory
- http://support.citrix.com/article/CTX134708
- [oss-security] 20120905 Xen Security Advisory 13 (CVE-2012-3495) - hypercall physdev_get_free_pirq vulnerability mailing-list
- SUSE-SU-2012:1133 vendor-advisory
- openSUSE-SU-2012:1573 vendor-advisory
- openSUSE-SU-2012:1172 vendor-advisory