CVE-2022-20770Network attack vector

Scanning service hang via CHM parser infinite loop

Published May 4, 2022 · Updated Nov 6, 2024

Denial of service in Cisco Secure Endpoint connectors with affected ClamAV libraries allows remote attackers to hang scans with crafted CHM files. The embedded ClamAV CHM parser enters an infinite loop while processing the malformed archive instead of terminating the scan with an error. No authentication or user interaction is required; the bounded consequence is loss of scanning availability, with no reported data exposure or modification.

CVSS severity8.6
High
EPSS probability6.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco Secure Endpoint connectors with affected ClamAV libraries allows remote attackers to hang scans with crafted CHM files. The embedded ClamAV CHM parser enters an infinite loop while processing the malformed archive instead of terminating the scan with an error. No authentication or user interaction is required; the bounded consequence is loss of scanning availability, with no reported data exposure or modification.

The record

CVE
CVE-2022-20770
Published
May 4, 2022
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco Secure Endpoint
Classifications
CWE-399, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Secure Endpointversion=n/a

Published CVSS scores

8.6CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-399Resource Management Errors
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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