4.7 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7 Medium
AI Score
Confidence
High
1.9 Low
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:N/I:N/A:P
0.0004 Low
EPSS
Percentile
12.3%
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.
lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/
security.gentoo.org/glsa/202011-06
www.debian.org/security/2020/dsa-4769
xenbits.xen.org/xsa/advisory-336.html
4.7 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7 Medium
AI Score
Confidence
High
1.9 Low
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:N/I:N/A:P
0.0004 Low
EPSS
Percentile
12.3%