MozillaApplication

CVE-2004-0871

MEDIUM · 5.0 CVSS v2.0 Published 2004-09-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Mozilla does not prevent cookies that are sent over an insecure channel (HTTP) from also being sent over a secure channel (HTTPS/SSL) in the same domain, which could allow remote attackers to steal cookies and conduct unauthorized activities, aka "Cross Security Boundary Cookie Injection."

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

Mozilla browser allows cookies set over insecure HTTP to also be sent over secure HTTPS channels within the same domain. This enables attackers on insecure networks to intercept cookies via HTTP and then use them to hijack authenticated HTTPS sessions, crossing the security boundary between insecure and secure channels.

MitigationUpdate or replace the affected Mozilla browser installation to a version that properly isolates HTTP cookies from HTTPS connections, or migrate to a modern browser that enforces secure cookie attributes.

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
MozillaApplication
Affected:= 0.9.2

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
None
Availability
None

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

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 Mozilla browser version
    Open the Mozilla browser and navigate to Help > About Mozilla, or check the application file properties of the Mozilla executable. Alternatively, run 'mozilla -version' from command line if available.
    Affected if The installed version is exactly 0.9.2
  2. Verify HTTP cookie leakage to HTTPS
    Visit a site over HTTP, then inspect cookies for that domain. Visit an HTTPS version of the same domain and check if those same cookies (without the 'secure' flag) are being sent in the HTTPS request.
    Affected if Cookies set over HTTP are being transmitted to HTTPS endpoints within the same domain, indicating the secure boundary is not enforced
  3. Check cookie attributes
    Using browser developer tools or a cookie inspector extension, examine cookies set by HTTP connections. Look for the 'secure' flag status on cookies from domains accessed via both HTTP and HTTPS.
    Affected if Cookies created during HTTP sessions lack the 'secure' attribute and are still sent when accessing HTTPS versions of the same domain

If running Mozilla version 0.9.2 and cookies set over insecure HTTP are being sent to secure HTTPS connections within the same domain, the environment is affected by this vulnerability.

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 or replace the affected Mozilla browser installation to a version that properly isolates HTTP cookies from HTTPS connections, or migrate to a modern browser that enforces secure cookie attributes.

Fix this in Mozilla Scoped from the published advisory
  • Consultation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
3.0 hours of engineering $750
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2004-0871 — 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-2004-0871 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
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