TI-2021-00979 Aliases CVE-2021-1252 GHSA-5qm5-4fjv-ghcw

Clam AntiVirus (ClamAV) Excel XLM Parser Denial of Service Vulnerability

MEDIUM 44CWE-20Published 2021-04-08 · Updated 2024-11-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-835.

Summary

A vulnerability in the Excel XLM macro parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper error handling that may result in an infinite loop. An attacker could exploit this vulnerability by sending a crafted Excel file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process hang, resulting in a denial of service condition.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.02516 84th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	ClamAV	0.103.0; 0.103.1	—	No fix listed	CNA

ClamAV VendorCisco Affected 0.103.0; 0.103.1 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:clamav:clamav:0.103.0:::::::*	0.103.0	Vulnerable	ClamAV
cpe:2.3:a:clamav:clamav:0.103.1:::::::*	0.103.1	Vulnerable	ClamAV

cpe:2.3:a:clamav:clamav:0.103.0:*:*:*:*:*:*:* Versions 0.103.0 Vulnerable ·ClamAV
cpe:2.3:a:clamav:clamav:0.103.1:*:*:*:*:*:*:* Versions 0.103.1 Vulnerable ·ClamAV

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Advisory · 2021-04-08
Cisco ClamAV — blog.clamav.net/2021/04/clamav-01032-security-patch-release…
3 records Highest priority Priority MEDIUM 3 MEDIUM
Other records, highest priority first
- TI-2021-01132 Clam AntiVirus (ClamAV) PDF Parser Denial of Service VulnerabilityPriority MEDIUM 44
- TI-2021-01131 Clam AntiVirus (ClamAV) Email Parser Denial of Service VulnerabilityPriority MEDIUM 43
Show all 3 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2021-1252
2026-10-03 Alias added: GHSA-5qm5-4fjv-ghcw

References

Advisory 1

https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html

TI-2026-74174 Arbitrary file write in Cisco Secure Email Gateway via AMP feature KEVCVSS 3.1CRITICAL 9.8
TI-2026-53490 Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53489 Cisco Secure Email Gateway SQL Injection Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16388 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16344 Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0

See all 7059 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences