CVE-2020-21674
CWE-787Published: October 15, 2020· Updated: Jun 17, 2026
Official Description
Heap-based buffer overflow in archive_string_append_from_wcs() (archive_string.c) in libarchive-3.4.1dev allows remote attackers to cause a denial of service (out-of-bounds write in heap memory resulting into a crash) via a crafted archive file. NOTE: this only affects users who downloaded the development code from GitHub. Users of the product's official releases are unaffected.
Technical Analysis
CVE-2020-21674 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.
From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-787)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-21674 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts