CVE-2021-3416: debian debian_linux Loop with Unreachable Exit Condition
Vulnerability summary
CVE-2021-3416 is a medium (CVSS 6.0) Loop with Unreachable Exit Condition vulnerability in debian debian_linux. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.7% 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 18 · Related 15Timeline
- 18-03-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.
CVSS metrics
5 scores · 4 sources · 2 versions- 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
0.46%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.46% 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.
Debian2 products
- qemu< 1:5.2+dfsg-9
- debian_linuxEOL9.0 | 10.0
Alpine1 product
- qemu< 6.0.0-r1
Fedoraproject1 product
- fedoraEOL33
Qemu1 product
- qemu≤ 5.2.0
Redhat1 product
- enterprise_linuxEOL6.0 | 7.0 | 8.0
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
6 vendors · 7 products
References
15 links- www.openwall.com/lists/oss-security/2021/02/26/1X Refsource MISCREPORTMailing ListPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2021/04/msg00009.htmlMailing ListX Refsource MLISTThird Party Advisory- lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing ListX Refsource MLISTThird Party Advisory
