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5.5
CVE-2021-28698: long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In ...
CVE-2021-28698 · published 5 years ago
Summary
long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones wh...
What to do
- Update debian xen to version 4.14.3-1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| – | xen | xen |
>= 3.2.0 cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* |
| – | fedoraproject | fedora |
33 34 35 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* |
| – | debian | debian_linux |
11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |
| Ubuntu:16.04:LTS | canonical | xen | All versions |
| Debian:12 | debian | xen |
< 4.14.3-1 Fix: upgrade to 4.14.3-1
|
Original advisory text
long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In ...
long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.
References
- http://www.openwall.com/lists/oss-security/2021/09/01/2 Mailing List Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...
- https://security.gentoo.org/glsa/202208-23 Third Party Advisory
- https://www.debian.org/security/2021/dsa-4977 Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-380.txt Vendor Advisory
- https://ubuntu.com/security/CVE-2021-28698 Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-380.html Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2021-28698 Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-28698 Vendor Advisory
Internet-facing
60 days
Internal
At next upgrade
- Not known to be exploited
- Needs hands-on effort to exploit (estimated)
- Gives an attacker partial control (estimated)
Type
CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
Timeline
Published27 Aug 2021
Updated4 Nov 2026
First seen29 Sep 2026
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