Anti VirusApplication · Sophos

CVE-2006-5645

MEDIUM · 5.0 CVSS v2.0 Published 2006-11-01
Fix available
A fix is available. Upgrade to after 6.04 or later.
See remediation →
59/100
Remediation priority · Elevated
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
Sophos Anti-Virus and Endpoint Security before 6.0.5, Anti-Virus for Linux before 5.0.10, and other platforms before 4.11, when "Enabled scanning of archives" is set, allows remote attackers to cause a denial of service (infinite loop) via a malformed RAR archive with an Archive Header section with the head_size and pack_size fields set to zero.

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 · high confidence

Sophos Anti-Virus and Endpoint Security products before versions 6.0.5, 5.0.10, and 4.11 contain a denial of service vulnerability in the RAR archive parsing module. When archive scanning is enabled (the default configuration), processing a malformed RAR file with zero-valued head_size and pack_size fields in the Archive Header triggers an infinite loop, causing CPU exhaustion and service unavailability.

MitigationMitigate by disabling the 'Enabled scanning of archives' configuration option in Sophos settings, or upgrade to the fixed versions (6.0.5 for Endpoint Security, 5.0.10 for Linux, 4.11 for other platforms).

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
Anti VirusApplication
Affected:= 4.04= 4.05= 4.5.3= 4.5.4= 4.5.11= 4.5.12= 4.7.1= 4.7.2= 5.0.1= 5.0.2= 5.0.4= 5.1
Endpoint SecurityApplication
Affected:<= 6.04

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

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 the installed Sophos product and version
    Check the installed version of Sophos Anti-Virus or Endpoint Security using the system's package manager, software inventory, or the Sophos management console. For Linux systems, run 'rpm -q sophos-antivirus' or 'dpkg -l sophos-antivirus'. On Windows, check Add/Remove Programs or the Sophos endpoint console.
    Affected if The installed version is any of: 4.04, 4.05, 4.5.3, 4.5.4, 4.5.11, 4.5.12, 4.7.1, 4.7.2, 5.0.1, 5.0.2, 5.0.4, 5.1 for Sophos Anti-Virus, or version 6.0.4 or earlier for Sophos Endpoint Security.
  2. Verify if archive scanning is enabled
    Check the Sophos configuration for the 'Enabled scanning of archives' or 'Scan archives' setting. On Windows, this is found in the Sophos Endpoint Security policy under 'Scanning' > 'Archive scanning'. On Linux, check the swee.conf or sav.conf configuration files for archive scanning directives.
    Affected if Archive scanning is enabled (this is the default configuration and is required for the vulnerability to be exploitable).

You are affected if you are running a vulnerable Sophos version (Anti-Virus 4.04-5.1 or Endpoint Security 6.0.4 and earlier) WITH archive scanning enabled.

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.

From vendor data
Upgrade available Upgrade to a release after 6.04
Interim mitigation

Mitigate by disabling the 'Enabled scanning of archives' configuration option in Sophos settings, or upgrade to the fixed versions (6.0.5 for Endpoint Security, 5.0.10 for Linux, 4.11 for other platforms).

Fix this in Anti Virus Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2006-5645 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2006-5645 in production — separate from our analysis above.

No notes yet

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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