Outlook ExpressApplication · Microsoft

CVE-2002-0285

HIGH · 7.5 CVSS v2.0 Published 2002-05-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Outlook Express 5.5 and 6.0 on Windows treats a carriage return ("CR") in a message header as if it were a valid carriage return/line feed combination (CR/LF), which could allow remote attackers to bypass virus protection and or other filtering mechanisms via a mail message with headers that only contain the CR, which causes Outlook to create separate headers.

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

Outlook Express 5.5 and 6.0 on Windows incorrectly handles malformed email headers containing only a carriage return (CR) character. While proper email headers should end with a CR/LF combination, Outlook Express treats a lone CR as a valid header terminator, causing it to parse what should be a single header as multiple separate headers. This parsing flaw allows attackers to embed malicious content or bypass filtering mechanisms that expect properly formatted headers.

MitigationApply Microsoft's security patch for this vulnerability; if patches are unavailable (Outlook Express is end-of-life), migrate to a supported email client such as Windows Mail, Mozilla Thunderbird, or Microsoft Outlook, and implement gateway-level email filtering to sanitize malformed headers before delivery.

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
Outlook ExpressApplication
Affected:= 5.5= 6.0

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
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/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 Outlook Express is installed
    Check for Outlook Express on the system by searching for 'outlook express' in Program Files or checking the Windows registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Outlook Express
    Affected if Outlook Express is found on the system and is the active email client
  2. Identify the installed Outlook Express version
    Open Outlook Express, click Help, then About Outlook Express to display the exact version number, or check the file version of mshtml.dll in the Windows System32 folder
    Affected if The version displayed is exactly 5.5 or 6.0 (no other versions are affected by this CVE)
  3. Confirm email client is actively configured
    Check if Outlook Express has any email accounts configured by examining the Identities or Account settings. If no accounts are set up, the parsing flaw cannot be exploited through incoming email
    Affected if Outlook Express 5.5 or 6.0 is installed and has at least one email account configured to receive mail

A user is affected if they have Microsoft Outlook Express version 5.5 or 6.0 installed and actively configured to receive email, as these specific versions incorrectly parse lone CR characters in email headers.

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

Apply Microsoft's security patch for this vulnerability; if patches are unavailable (Outlook Express is end-of-life), migrate to a supported email client such as Windows Mail, Mozilla Thunderbird, or Microsoft Outlook, and implement gateway-level email filtering to sanitize malformed headers before delivery.

Fix this in Outlook Express Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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Scan for this in your stack

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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-2002-0285 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