CVE-2020-25604An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating…
- 4.7MediumCVSS base score
- 0.26%Exploitation in 30 daysEPSS · top 82% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By mitre
- 7 days later
· 7 days later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.26% · top 82% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.7.
Affected products
n/a
- affected n/a
References
References7
- https://xenbits.xen.org/xsa/advisory-336.html (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2020-306b84fd07 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2020-f668e579be (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- DSA-4769 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- openSUSE-SU-2020:1608 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- FEDORA-2020-d46fe34349 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- GLSA-202011-06 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-18283 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-25604)Record last updated .