CVE-2020-25599
There are evtchn_reset() race conditions.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An issue was discovered in Xen through 4.14.x. There are evtchn_reset() race conditions. Uses of EVTCHNOP_reset (potentially by a guest on itself) or XEN_DOMCTL_soft_reset (by itself covered by XSA-77) can lead to the violation of various internal assumptions. This may lead to out of bounds memory accesses or triggering of bug checks. In particular, x86 PV guests may be able to elevate their privilege to that of the host. Host and guest crashes are also possible, leading to a Denial of Service (DoS). Information leaks cannot be ruled out. All Xen versions from 4.5 onwards are vulnerable. Xen versions 4.4 and earlier are not vulnerable.
- CVSS 3.1
- 7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.29% probability · 21th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-119, CWE-362
- Affected
- xen/xen · fedoraproject/fedora · opensuse/leap · debian/debian linux
- Source
- cve@mitre.org
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.htmlMailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/12/16/5Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/
- https://security.gentoo.org/glsa/202011-06Third Party Advisory
- https://www.debian.org/security/2020/dsa-4769Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-343.htmlPatch, Vendor Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.htmlMailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/12/16/5Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/
- https://security.gentoo.org/glsa/202011-06Third Party Advisory
- https://www.debian.org/security/2020/dsa-4769Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-343.htmlPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.