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.
CVE-2021-28698
Score 5.5 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.5; sources differ by 0.0.
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.5
- EG Score
- 5.5(medium)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity55% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 27.5%
- KEV
- Not listed
Published
August 27, 2021
Last Modified
November 21, 2024
References (14)
- security@xenhttp://www.openwall.com/lists/oss-security/2021/09/01/2
- security@xenhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/
- security@xenhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/
- security@xenhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/
- security@xenhttps://security.gentoo.org/glsa/202208-23
- security@xenhttps://www.debian.org/security/2021/dsa-4977
- security@xenhttps://xenbits.xenproject.org/xsa/advisory-380.txt
- af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/09/01/2
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/
- af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202208-23
- af854a3a-2127-422b-91ae-364da2661108https://www.debian.org/security/2021/dsa-4977
- af854a3a-2127-422b-91ae-364da2661108https://xenbits.xenproject.org/xsa/advisory-380.txt
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 50× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 101 total refreshes for this CVE.
- 2026-07-23 01:59 UTCEG score recompute
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Frequently asked(5)
What is CVE-2021-28698?
When was CVE-2021-28698 disclosed?
Is CVE-2021-28698 actively exploited?
What is the CVSS score of CVE-2021-28698?
How do I remediate CVE-2021-28698?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-28698
Is Your Infrastructure Affected by CVE-2021-28698?
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