CVE-2020-25601
An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO…
- Published
- Updated
- Reserved
- Assigned by
- mitre
Description
An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.
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 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.42% · top 63% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
- n/a
Affected products
n/a
- affected n/a
References (7)
- https://xenbits.xen.org/xsa/advisory-344.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)
- 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://trackcve.app/cve/CVE-2020-25601)Record last updated .