CVE-2021-20221: debian debian_linux Out-of-bounds Read
Vulnerability summary
CVE-2021-20221 is a medium (CVSS 6.0) Out-of-bounds Read vulnerability in debian debian_linux. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.
Not severe (CVSS 6, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 16 · Related 13Timeline
- 13-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
An out-of-bounds heap buffer access issue was found in the ARM Generic Interrupt Controller emulator of QEMU up to and including qemu 4.2.0on aarch64 platform. The issue occurs because while writing an interrupt ID to the controller memory area, it is not masked to be 4 bits wide. It may lead to the said issue while updating controller state fields and their subsequent processing. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.
CVSS metrics
6 scores · 5 sources · 2 versions- OSV · Red hatEcosystem advisory · calculated2.5LowCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:LDiffers
- OSV · UbuntuEcosystem advisory · calculated6.0MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.0MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
- OSV · AlpineEcosystem advisory · calculated6.0MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
EPSS trend
Probability
0.33%
Chance of exploitation in the next 30 days
Percentile
26%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.33% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, administrative account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Redhat195 products
- enterprise_linux8.0
- hivex< 0:1.3.18-20.module+el8.3.0+6124+819ee737
- hivex-debuginfo< 0:1.3.18-20.module+el8.3.0+6124+819ee737
- hivex-debugsource< 0:1.3.18-20.module+el8.3.0+6124+819ee737
- hivex-devel< 0:1.3.18-20.module+el8.3.0+6124+819ee737
Debian2 products
- qemu< 1:5.2+dfsg-4
- debian_linuxEOL9.0 | 10.0
Alpine1 product
- qemu< 5.0.0-r0
Qemu1 product
- qemu≤ 4.2.0
Ubuntu1 product
- qemu< 2.0.0+dfsg-2ubuntu1.47+esm6 | < 1:2.5+dfsg-5ubuntu10.51+esm4 | < 1:2.11+dfsg-1ubuntu7.37 | < 1:4.2-3ubuntu6.17
5 vendors · 200 products · Showing 200 of 234
References
20 links- www.openwall.com/lists/oss-security/2021/02/05/1Mailing ListX Refsource MLISTPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2021/02/msg00024.htmlMailing ListX Refsource MLISTThird Party Advisory- bugzilla.redhat.com/show_bug.cgi?id=1924601X Refsource MISCREPORTIssue TrackingPatchThird Party Advisory
- lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing ListX Refsource MLISTThird Party Advisory
