CommunicatorApplication · Netscape

CVE-1999-0809

MEDIUM · 5.0 CVSS v2.0 Published 1999-07-09
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
Netscape Communicator 4.x with Javascript enabled does not warn a user of cookie settings, even if they have selected the option to "Only accept cookies originating from the same server as the page being viewed".

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

Netscape Communicator 4.x fails to enforce user-configured cookie privacy settings when JavaScript is used to set cookies. Despite a user explicitly selecting the option to only accept cookies from the originating server, JavaScript can set third-party cookies without warning or enforcement, bypassing the user's privacy preference.

MitigationThis vulnerability affects an obsolete, unsupported product (Netscape Communicator 4.x). The only practical remediation is to migrate to a modern, supported web browser that properly enforces cookie privacy settings.

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
CommunicatorApplication
Affected:= 4.0

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
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 Netscape Communicator installation
    Check if Netscape Communicator 4.x is installed on the system by looking for the browser executable or checking installed programs. On Windows, look for 'C:\Program Files\Netscape\Communicator\' or similar paths.
    Affected if Netscape Communicator 4.0 is installed and in use
  2. Verify browser version
    Launch Netscape Communicator and check Help > About to confirm version 4.0 specifically.
    Affected if Version is exactly 4.0 (other 4.x versions may also be affected but this is the confirmed affected version)
  3. Check cookie privacy configuration
    In Netscape Communicator, go to Edit > Preferences > Privacy & Security > Cookies. Look for the setting controlling cookie acceptance.
    Affected if Cookie privacy is configured to 'only accept cookies from the originating server' or equivalent restrictive setting
  4. Check JavaScript enablement
    In Netscape Communicator, go to Edit > Preferences > Advanced > Scripts & Plugins. Verify if JavaScript (or Java) is enabled.
    Affected if JavaScript is enabled in the browser settings

A user is affected if they run Netscape Communicator 4.0 with JavaScript enabled and have configured cookie privacy to restrict third-party cookies, as JavaScript can bypass this setting.

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

This vulnerability affects an obsolete, unsupported product (Netscape Communicator 4.x). The only practical remediation is to migrate to a modern, supported web browser that properly enforces cookie privacy settings.

Fix this in Communicator Scoped from the published advisory
  • Consultation1.0 h
  • Review / QA1.0 h
2.0 hours of engineering $750
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-1999-0809 — 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-1999-0809 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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