CVE-2021-33643

CVE-2021-33643 is a critical-severity vulnerability in Feep Libtar with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

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.

Frequently asked questions

What is CVE-2021-33643?
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.
How severe is CVE-2021-33643?
CVE-2021-33643 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2021-33643 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33643?
CVE-2021-33643 primarily affects Feep Libtar. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33643?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-33643 published?
CVE-2021-33643 was published on 2022-08-10 and last updated on 2026-06-23.

References

Affected products (7)

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