CVE-2025-20128: ClamAV OLE2 File Format Decryption Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-01-22 · updated 2026-06-17
Weakness: CWE-122

Description

A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an integer underflow in a bounds check that allows for a heap buffer overflow read. An attacker could exploit this vulnerability by submitting a crafted file containing OLE2 content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process, resulting in a DoS condition on the affected software. For a description of this vulnerability, see the . Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Affected products

Cisco Secure Endpoint: before 1.24.4; before 1.25.1; before 7.5.20; from 8.0.1.21160 before 8.4.3 — fixed in 1.24.4, 1.25.1, 7.5.20, 8.4.3
Cisco Secure Endpoint Private Cloud: before 4.2.0 — fixed in 4.2.0
Cisco ClamAV: from 1.0.0 before 1.0.8; from 1.1.0 before 1.4.2 — fixed in 1.0.8, 1.4.2

How to fix

Upgrade to a fixed version: Cisco Secure Endpoint 1.24.4, 1.25.1, 7.5.20, 8.4.3; Cisco Secure Endpoint Private Cloud 4.2.0; Cisco ClamAV 1.0.8, 1.4.2. Check the vendor advisory for mitigations.

References

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