CVE-2020-25604
An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.
EPSS 0.07% · 21.9th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:16.04:LTS | xen | 0, 4.5.1-0ubuntu1, 4.5.1-0ubuntu2 |
| Ubuntu:20.04:LTS | xen | 4.11.3+24-g14b62ab3e5-1ubuntu2.2, 4.9.2-0ubuntu6, 4.9.2-0ubuntu7 |
| Ubuntu:18.04:LTS | xen | 4.9.0-0ubuntu3, 4.9.0-0ubuntu4, 4.9.2-0ubuntu1 |
Timeline
- Sep 23, 2020 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 22, 2021 EPSS Score
- Aug 24, 2021 EPSS Score
- Oct 25, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Feb 27, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- May 1, 2022 EPSS Score
- Jul 2, 2022 EPSS Score
- Sep 4, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2020-25604 third-party-advisory
- https://xenbits.xen.org/xsa/advisory-336.html third-party-advisory
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/ third-party-advisory
- https://ubuntu.com/security/notices/USN-5617-1 vendor-advisory
- https://www.cve.org/CVERecord?id=CVE-2020-25604 third-party-advisory