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Secure EndpointApplication · Cisco

CVE-2022-20770

HIGH · 7.5 CVSS v3.1 Published 2022-05-04
Fix available
A fix is available. Upgrade to 1.16.3 / 1.17.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
On April 20, 2022, the following vulnerability in the ClamAV scanning library versions 0.103.5 and earlier and 0.104.2 and earlier was disclosed: A vulnerability in CHM file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. For a description of this vulnerability, see the ClamAV blog. This advisory will be updated as additional information becomes available.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A vulnerability in the CHM (Compiled HTML Help) file parser of ClamAV versions 0.104.0-0.104.2 and 0.103.5 and prior allows an unauthenticated remote attacker to cause a denial of service by processing a specially crafted CHM file, likely through a parsing error leading to excessive resource consumption or crash.

MitigationUpdate ClamAV to version 0.103.6, 0.104.3, or later to patch the vulnerability. If CHM scanning is not required in the environment, it can be disabled as a compensating control.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Secure EndpointApplication
Affected:< 1.16.3< 1.17.2< 7.5.5>= 1.18.0, < 1.18.2
FedoraOperating system
Affected:= 34= 35= 36
Debian LinuxOperating system
Affected:= 9.0
ClamavApplication
Affected:<= 0.103.5>= 0.104.0, <= 0.104.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify ClamAV version
    Run 'clamscan --version' or 'clamd --version' to obtain the installed ClamAV version number
    Affected if The version falls within <= 0.103.5, or >= 0.104.0 and <= 0.104.2
  2. Check operating system package version
    For Debian-based systems, run 'dpkg -l | grep clamav'; for RHEL/Fedora-based systems, run 'rpm -qa | grep clamav'
    Affected if The packaged version matches the affected ClamAV ranges (0.103.5 and prior, or 0.104.0-0.104.2)
  3. Verify CHM scanning is enabled
    Inspect the ClamAV daemon configuration (typically /etc/clamd/clamd.conf or /etc/clamav/clamd.conf) for CHM-related settings or scanning directives
    Affected if CHM scanning is enabled and the ClamAV version is vulnerable
  4. Confirm clamd service is running
    Check if the clamd service is active using 'systemctl status clamd' or 'service clamd status'
    Affected if clamd is actively scanning files including CHM files with a vulnerable ClamAV version

You are affected if ClamAV version 0.103.5 or prior, or version 0.104.0 through 0.104.2 is installed AND CHM file scanning is enabled in your ClamAV configuration.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.16.3 / 1.17.2 / 1.18.2 or later
Fixed in 1.16.31.17.21.18.2
Interim mitigation

Update ClamAV to version 0.103.6, 0.104.3, or later to patch the vulnerability. If CHM scanning is not required in the environment, it can be disabled as a compensating control.

Recommended fix High confidence

ClamAV 0.103.6 (LTS) or ClamAV 0.104.3+

  1. 1. Identify the currently installed ClamAV version using: `clamd --version` or `freshclam --version`
  2. 2. For ClamAV 0.103.x (LTS) users: upgrade to version 0.103.6 or later (e.g., `apt-get install clamav=0.103.6` or equivalent for your package manager)
  3. 3. For ClamAV 0.104.x users: upgrade to version 0.104.3 or later
  4. 4. After upgrade, restart the clamd daemon: `systemctl restart clamd` or `service clamd restart`
  5. 5. Verify the new version is running: `clamd --version`
  6. 6. Update signature database after upgrade: `freshclam`
Caveat Minor - this is a bug fix and DoS patch; ensureclamd is restarted to load the fixed library

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Secure Endpoint Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-20770 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data