9.8

CVE-2021-33640: fedoraproject fedora Use After Free

Modified
AliasesMGASA-2022-0488
Published 19-12-2022Last modified 17-04-2025

Vulnerability summary

CVE-2021-33640 is a critical (CVSS 9.8) Use After Free vulnerability in fedoraproject fedora. EPSS estimates a 0.69% chance of exploitation in the next 30 days, higher than 53% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.2, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.69%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:11092-1

Timeline

  1. 19-12-2022
    PublishedVulnerability first disclosed.
  2. 17-04-2025
    Last modifiedVulnerability information updated.

Description

After tar_close(), libtar.c releases the memory pointed to by pointer t. After tar_close() is called in the list() function, it continues to use pointer t: free_longlink_longname(t->th_buf) . As a result, the released memory is used (use-after-free).

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.69%

Chance of exploitation in the next 30 days

Percentile

53%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 0.67% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Openeuler3 products
Fedoraproject1 product
Mageia1 product
  • libtar< 1.2.20-9.2.mga8
Openatom1 product

4 vendors · 6 products

References

7 links