What’s Vulnerable › Vulnerabilities

CVE-2021-33640

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-12-19 · updated 2026-06-17
• Weakness: CWE-416

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).

Affected products

• Fedoraproject Fedora: 36, 37
• Openatom Openeuler: 20.03-sp1, 20.03-sp2, 22.03

References

• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4S4PJRCJLEAWN2EKXGLSOBTL7O57V7NC/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7WX5YE66CT7Y5C2HTHXSFDKQWYWYWJ2T/
• https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2021-33640&packageName=libtar
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4S4PJRCJLEAWN2EKXGLSOBTL7O57V7NC/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7WX5YE66CT7Y5C2HTHXSFDKQWYWYWJ2T/
• https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2021-33640&packageName=libtar

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