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Internet Security SuiteApplication · Mcafee

CVE-2005-3377

MEDIUM · 5.1 CVSS v2.0 Published 2005-10-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
60/100
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
Multiple interpretation error in (1) McAfee Internet Security Suite 7.1.5 version 9.1.08 with the 4.4.00 engine and (2) McAfee Corporate 8.0.0 patch 10 with the 4400 engine allows remote attackers to bypass virus scanning via a file such as BAT, HTML, and EML with an "MZ" magic byte sequence which is normally associated with EXE, which causes the file to be treated as a safe type that could still be executed as a dangerous file type by applications on the end system, as demonstrated by a "triple headed" program that contains EXE, EML, and HTML content, aka the "magic byte bug."

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

McAfee antivirus products misidentify file types by examining magic bytes at the start of files. Attackers embed executable 'MZ' headers (normally EXE signatures) inside files with extensions like BAT, HTML, or EML, causing the scanner to treat them as safe while the content can still be executed by end-user applications. This 'triple-headed' attack bypasses virus scanning by exploiting the mismatch between file extension/format and actual executable content.

MitigationUpdate McAfee products to versions with corrected file type detection logic, and implement application whitelisting or execution restrictions on user-accessible directories to block unexpected executable runs regardless of file container.

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
Internet Security SuiteApplication
Affected:= 7.1.5_version_9.1.08_engine_4.4.00= 8.0.0_patch_10_engine_4400

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
High
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:H/Au:N/C:P/I:P/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. Verify McAfee Internet Security Suite is installed
    Check for McAfee installation via program files directory, registry key (HKLM\SOFTWARE\McAfee\Inc. or similar), or by querying installed programs (e.g., 'wmic product get name,version' on Windows)
    Affected if McAfee Internet Security Suite is found on the system
  2. Retrieve the exact version of McAfee Internet Security Suite
    Use McAfee's version information tool (e.g., 'mconame -version' or check About section in McAfee GUI), or locate version in registry under HKLM\SOFTWARE\McAfee\AVS or the product's main executable properties
    Affected if Version matches or falls within: 7.1.5_version_9.1.08_engine_4.4.00 or 8.0.0_patch_10_engine_4400
  3. Confirm file type detection uses magic byte analysis
    This is inherent to the antivirus scanning engine; no configuration toggle exists. The vulnerability exists in how the scanner identifies file types by examining the first bytes of files (MZ header for executables) rather than relying solely on file extension
    Affected if The installed version matches the affected versions AND the scanner is actively scanning files using magic byte detection (default behavior)
  4. Identify if user-accessible directories allow file execution
    Inspect folder permissions on common writeable locations (e.g., user Downloads, Temp, Desktop) using 'icacls' command or check Group Policy settings under Computer Configuration > Windows Settings > Security Settings > Software Restriction Policies
    Affected if Users can save and execute files from accessible directories, allowing the 'triple-headed' attack to succeed if a malicious file is introduced

The environment is affected if McAfee Internet Security Suite version 7.1.5_version_9.1.08_engine_4.4.00 or 8.0.0_patch_10_engine_4400 is installed and the antivirus is performing file type detection based on magic bytes, with users having executable permissions in writable directories.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update McAfee products to versions with corrected file type detection logic, and implement application whitelisting or execution restrictions on user-accessible directories to block unexpected executable runs regardless of file container.

Fix this in Internet Security Suite Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2005-3377 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
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  • Version or environment caveats, and links to real fixes
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