CVE-2026-20214: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') in Cisco Cisco Secure Endpoint
A vulnerability in the FSG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in FSG files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains portable executable content compressed with FSG to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.
AI Analysis
Technical Summary
This vulnerability arises from improper boundary checks in the FSG file format parser within ClamAV used by Cisco Secure Endpoint. When scanning crafted files containing portable executable content compressed with FSG, the parser may perform an out-of-bounds buffer write, causing memory corruption. Exploitation results in termination of the ClamAV scanning process, causing a denial-of-service condition. The vulnerability is remotely exploitable without authentication and affects many exact versions of Cisco Secure Endpoint as listed. There is no vendor advisory indicating an available patch or fix at this time.
Potential Impact
Successful exploitation causes the ClamAV scanning process on Cisco Secure Endpoint to terminate unexpectedly, resulting in a denial-of-service condition. There is no confirmed impact on confidentiality or integrity. The vulnerability does not require authentication and can be triggered remotely by submitting crafted files for scanning.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider restricting or monitoring file submissions to the scanning engine to reduce exposure to crafted FSG files. No official remediation or temporary fix is currently documented.
CVE-2026-20214: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') in Cisco Cisco Secure Endpoint
Description
A vulnerability in the FSG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in FSG files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains portable executable content compressed with FSG to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.
CVSS v3.1
Score 7.5high
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability arises from improper boundary checks in the FSG file format parser within ClamAV used by Cisco Secure Endpoint. When scanning crafted files containing portable executable content compressed with FSG, the parser may perform an out-of-bounds buffer write, causing memory corruption. Exploitation results in termination of the ClamAV scanning process, causing a denial-of-service condition. The vulnerability is remotely exploitable without authentication and affects many exact versions of Cisco Secure Endpoint as listed. There is no vendor advisory indicating an available patch or fix at this time.
Potential Impact
Successful exploitation causes the ClamAV scanning process on Cisco Secure Endpoint to terminate unexpectedly, resulting in a denial-of-service condition. There is no confirmed impact on confidentiality or integrity. The vulnerability does not require authentication and can be triggered remotely by submitting crafted files for scanning.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider restricting or monitoring file submissions to the scanning engine to reduce exposure to crafted FSG files. No official remediation or temporary fix is currently documented.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2025-10-08T11:59:15.398Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a45492827e9c79719d62045
Added to database: 07/01/2026, 17:06:48 UTC
Last enriched: 07/01/2026, 17:36:50 UTC
Last updated: 07/01/2026, 21:25:37 UTC
Views: 6
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