Norman Virus ControlApplication · Norman

CVE-2005-3378

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 Norman 5.81 with the 5.83.02 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

The Norman Antivirus 5.81/5.83.02 engine has a magic byte interpretation flaw where files with 'MZ' headers (normally EXE signature) are misclassified as safe, even when containing malicious BAT, HTML, or EML content. This 'triple-headed' attack allows malware to bypass virus scanning by exploiting the file type detection logic.

MitigationReplace obsolete Norman antivirus with current endpoint protection; implement application whitelisting and disable automatic execution of email attachments as compensating controls until replacement is feasible.

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
Norman Virus ControlApplication
Affected:= 5.81_engine_5.83.02

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 Norman Antivirus is installed
    Check system for installed Norman Virus Control software via Programs and Features, registry key HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall, or installed security software enumeration
    Affected if Norman Virus Control appears in installed programs
  2. Identify Norman Virus Control version
    Open Norman Virus Control UI and navigate to About/Help, or check registry key for DisplayVersion under the Norman uninstall entry
    Affected if Version displays as 5.81 with engine 5.83.02
  3. Confirm engine version specifically
    Within Norman Virus Control interface, locate engine/detection engine version information typically found in Settings or About section
    Affected if Engine version reports as exactly 5.83.02
  4. Verify product is actively scanning
    Confirm Norman Virus Control real-time scanning or on-demand scanner is enabled and operational
    Affected if Scanning is active and processing files with MZ headers as safe

User is affected if Norman Virus Control version 5.81 with engine 5.83.02 is installed and its file type detection is actively processing files.

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

Replace obsolete Norman antivirus with current endpoint protection; implement application whitelisting and disable automatic execution of email attachments as compensating controls until replacement is feasible.

Fix this in Norman Virus Control Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $10,240.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2005-3378 — 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-2005-3378 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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