Use-after-free vulnerability in the FIFO event channel code in Xen 4.4.x allows local guest OS administrators to cause a denial of service (host crash) and possibly execute arbitrary code or obtain sensitive information via an invalid guest frame number.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xen | Xen | 4.4.0 (including) | 4.4.0 (including) |
| Xen | Xen | 4.4.1 (including) | 4.4.1 (including) |
| Xen | Xen | 4.4.2 (including) | 4.4.2 (including) |
| Xen | Xen | 4.4.3 (including) | 4.4.3 (including) |
| Xen | Xen | 4.4.4 (including) | 4.4.4 (including) |
| Xen | Ubuntu | trusty | * |
Potential Mitigations
References
- http://support.citrix.com/article/CTX216071
- http://www.c7zero.info/stuff/csw2017_ExploringYourSystemDeeper_updated.pdf
- http://www.debian.org/security/2016/dsa-3663
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
- http://www.securityfocus.com/bid/92863
- http://www.securitytracker.com/id/1036754
- http://xenbits.xen.org/xsa/advisory-188.html
- http://xenbits.xen.org/xsa/xsa188.patch
- http://support.citrix.com/article/CTX216071
- http://www.c7zero.info/stuff/csw2017_ExploringYourSystemDeeper_updated.pdf
- http://www.debian.org/security/2016/dsa-3663
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
- http://www.securityfocus.com/bid/92863
- http://www.securitytracker.com/id/1036754
- http://xenbits.xen.org/xsa/advisory-188.html
- http://xenbits.xen.org/xsa/xsa188.patch