CVE-2008-5541
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 · uneditedSophos Anti-Virus 4.33.0, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.
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 confidenceSophos Anti-Virus 4.33.0 fails to properly detect malware embedded in HTML documents when the file contains an MZ header (EXE marker) at the beginning and uses a non-executable or misleading file extension (.txt, .jpg, or no extension). This allows malicious HTML documents containing exploits like CVE-2006-5745 to bypass antivirus scanning.
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= 4.33.0CVSS 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
- M
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:M/Au:N/C:C/I:C/A:C
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 checksWork through these to decide whether this CVE applies to you.
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Verify Sophos Anti-Virus versionCheck the installed version of Sophos Anti-Virus on the system. On Windows, this is typically found in Add/Remove Programs, the Sophos GUI under 'About', or via command line if available. Compare the version number to 4.33.0.Affected if The installed version is exactly 4.33.0
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Confirm HTML scanning behavior with test fileCreate or obtain a test HTML file that contains an MZ header (EXE marker) at the beginning but has a non-executable extension like .txt, .jpg, or no extension. Scan this file with the installed Sophos Anti-Virus and verify if it is detected as malicious.Affected if The scanner fails to detect the malicious HTML file containing an embedded MZ header
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Check antivirus definition version and dateInspect the Sophos Anti-Virus definition files and their date. This is typically visible in the Sophos GUI or via command line interface. Note the definition version and date of the last update.Affected if The antivirus definitions are outdated or the version does not include fixes for CVE-2006-5745 detection in HTML files
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Review scanning configuration for HTML content inspectionExamine the Sophos Anti-Virus scanning configuration to determine if deep content scanning (also known as 'scan inside files' or 'deep file analysis') is enabled for HTML documents. This setting controls whether the scanner inspects file content regardless of file extension.Affected if Deep content scanning for HTML files is disabled or misconfigured, allowing files to be scanned by extension only
A system is affected if Sophos Anti-Virus version 4.33.0 is installed and HTML files containing embedded MZ headers with misleading extensions bypass the antivirus scanner.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade Sophos Anti-Virus to a version beyond 4.33.0 that properly inspects file content regardless of extension and detects HTML files containing embedded executable code or MZ headers. Ensure antivirus definitions are current.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2008-5541 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2008-5541 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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