Heap-based buffer overflow in archive_string_append_from_wcs() (archive_string.c) in…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libarchive:libarchive:3.4.1:*:*:*:*:*:*:* | 3.4.1 | Vulnerable | libarchive |
- cpe:2.3:a:libarchive:libarchive:3.4.1:*:*:*:*:*:*:* Versions 3.4.1 Vulnerable ·libarchive
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
Not affected: 1 product
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2020-21674
- 2026-10-03 Alias added: GHSA-crq5-4m3r-9jx2
References
More Libarchive vulnerabilities
- TI-2024-17342 Libarchive Remote Code Execution Vulnerability CVSS 3.1HIGH 7.8
- TI-2024-24911 Libarchive before 3.7.4 allows name out-of-bounds access when a ZIP archive has an… CVSS 3.1CRITICAL 9.1
- TI-2025-05340 Libarchive: double free at archive_read_format_rar_seek_data() in archive_read_support_format_rar.c CVSS 3.1HIGH 7.8
- TI-2024-32437 Null Pointer Dereference vulnerability in libarchive 3.7.6 and earlier when running… CVSS 3.1HIGH 7.5
- TI-2025-37810 An issue was discovered in libarchive bsdtar before version 3.8.1 in function… CVSS 3.1MEDIUM 5.5
- TI-2025-01402 libarchive bsdunzip.c list null pointer dereference CVSS 4.0MEDIUM 4.8
Sources
- CVE-2020-21674 · CVE Program
- CVE-2020-21674 · NVD
- FIRST EPSS
- GHSA-crq5-4m3r-9jx2 · GitHub Advisory Database · CC BY 4.0
- CVE-2020-21674 · Red Hat security data · CC BY 4.0
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