Description
Xen 4.4.x, when running on an ARM system, does not properly context switch the CNTKCTL_EL1 register, which allows local guest users to modify the hardware timers and cause a denial of service (crash) 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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | xen | 4.4.0-0ubuntu5.1 | — |
References
- 67157 vdb-entry
- http://xenbits.xen.org/xsa/advisory-91.html
- [oss-security] 20140430 Xen Security Advisory 91 - Hardware timer context is not properly context switched on ARM mailing-list
- 1030184 vdb-entry
- [oss-security] 20140430 Re: Xen Security Advisory 91 - Hardware timer context is not properly context switched on ARM mailing-list
- 58347 third-party-advisory