CVE-2021-33643: fedoraproject fedora Out-of-bounds Read
Vulnerability summary
CVE-2021-33643 is a critical (CVSS 9.1) Out-of-bounds Read vulnerability in fedoraproject fedora. EPSS estimates a 1.88% chance of exploitation in the next 30 days, higher than 79.4% of scored vulnerabilities.
Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 5 · Related 2Timeline
- 09-08-2022PublishedVulnerability first disclosed.
- 23-06-2026Last modifiedVulnerability information updated.
Description
An attacker who submits a crafted tar file with size in header struct being 0 may be able to trigger an calling of malloc(0) for a variable gnu_longlink, causing an out-of-bounds read.
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:LDiffers
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:LDiffers
- OSV · DebianEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
1.88%
Chance of exploitation in the next 30 days
Percentile
79%
Versus all other CVEs
30-day change
Increase +0.10 pp
From 1.77% 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: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- libtar< 1.2.20-8+deb12u1
Fedoraproject1 product
- fedoraEOL35 | 36 | 37
Feep1 product
- libtar< 1.2.21
Openatom1 product
- openeuler20.03:sp1 | 20.03:sp3 | 22.03
Ubuntu1 product
- libtar< 1.2.20-4ubuntu0.1~esm1 | < 1.2.20-7ubuntu0.1~esm1 | < 1.2.20-8ubuntu0.20.04.1 | < 1.2.20-8ubuntu0.22.04.1 | < 1.2.20-8.1ubuntu0.24.04.1
5 vendors · 5 products
References
13 links- www.openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2022-1807Broken LinkThird Party Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
