4.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
0.0004 Low
EPSS
Percentile
14.2%
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.
Author | Note |
---|---|
mdeslaur | hypervisor packages are in universe. For issues in the hypervisor, add appropriate tags to each section, ex: Tags_xen: universe-binary |
launchpad.net/bugs/cve/CVE-2020-25601
lists.fedoraproject.org/archives/list/[email protected]/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/
nvd.nist.gov/vuln/detail/CVE-2020-25601
security-tracker.debian.org/tracker/CVE-2020-25601
ubuntu.com/security/notices/USN-5617-1
www.cve.org/CVERecord?id=CVE-2020-25601
xenbits.xen.org/xsa/advisory-344.html
4.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
0.0004 Low
EPSS
Percentile
14.2%