An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service or gain privileges by leveraging the erroneous enabling of interrupts. Interrupts are unconditionally unmasked in exception handlers. When an exception occurs on an ARM system which is handled without changing processor level, some interrupts are unconditionally enabled during exception entry. So exceptions which occur when interrupts are masked will effectively unmask the interrupts. A malicious guest might contrive to arrange for critical Xen code to run with interrupts erroneously enabled. This could lead to data corruption, denial of service, or possibly even privilege escalation. However a precise attack technique has not been identified.
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
| Link | Tags |
|---|---|
| http://xenbits.xen.org/xsa/advisory-303.html | patch vendor advisory |
| http://www.openwall.com/lists/oss-security/2019/10/31/5 | patch mailing list third party advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/ | vendor advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/ | vendor advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/ | vendor advisory |
| https://www.debian.org/security/2020/dsa-4602 | third party advisory vendor advisory |
| https://seclists.org/bugtraq/2020/Jan/21 | third party advisory mailing list |