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This vulnerability has been modified since it was last analyzed by the NVD. It is awaiting reanalysis which may result in further changes to the information provided.
Description
An issue was discovered in Xen through 4.14.x. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
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OR
*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
Added
CPE Configuration
OR
*cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
Changed
CPE Configuration
OR
*cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
*cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
*cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
OR
*cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
*cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
*cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
Changed
Reference Type
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html Mailing List, Third Party Advisory
Changed
Reference Type
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/ Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/ Mailing List, Third Party Advisory
Changed
Reference Type
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/ Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/ Mailing List, Third Party Advisory
Changed
Reference Type
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/ No Types Assigned
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/ Mailing List, Third Party Advisory
Changed
Reference Type
https://security.gentoo.org/glsa/202011-06 No Types Assigned
https://security.gentoo.org/glsa/202011-06 Third Party Advisory