An issue (known as XSA-212) was discovered in Xen, with fixes available for 4.8.x, 4.7.x, 4.6.x, 4.5.x, and 4.4.x. The earlier XSA-29 fix introduced an insufficient check on XENMEM_exchange input, allowing the caller to drive hypervisor memory accesses outside of the guest provided input/output arrays.
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
| Link | Tags |
|---|---|
| http://www.securityfocus.com/bid/97375 | vdb entry third party advisory |
| http://xenbits.xen.org/xsa/advisory-212.html | patch vendor advisory |
| http://openwall.com/lists/oss-security/2017/04/04/3 | third party advisory mailing list |
| https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-029-2017.txt | |
| http://www.debian.org/security/2017/dsa-3847 | vendor advisory |
| https://www.exploit-db.com/exploits/41870/ | exploit |
| https://googleprojectzero.blogspot.com/2017/04/pandavirtualization-exploiting-xen.html | third party advisory technical description |
| http://www.securitytracker.com/id/1038223 | vdb entry |