CVE-1999-0142
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 · uneditedThe Java Applet Security Manager implementation in Netscape Navigator 2.0 and Java Developer's Kit 1.0 allows an applet to connect to arbitrary hosts.
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 confidenceThe Java Applet Security Manager in Netscape Navigator 2.0 and JDK 1.0 failed to properly restrict applet network connections, allowing malicious applets to connect to arbitrary hosts rather than being limited to their origin server. This sandbox bypass vulnerability enables applets to make outbound network connections to any system, potentially facilitating data exfiltration or attacks against internal network resources.
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 dataall versionsall versionsCVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify Netscape Navigator installationSearch for netscape.exe or related executable files in common installation directories (C:\Program Files\Netscape, /Applications/Netscape, /usr/lib/netscape) and check the application's About dialog if accessibleAffected if Netscape Navigator is installed and running
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Check Java runtime versionRun 'java -version' or 'java -fullversion' from command line to identify the installed JRE/JDK versionAffected if Version string shows 1.0.x or early 1.1.x releases (JDK 1.0 / Java 1.0)
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Verify Java applet execution environmentCheck if Java Plugin Control Panel shows applet support enabled, or examine browser plugin settings for Java Applet Plug-inAffected if Java applets are enabled and the browser uses the legacy Java plugin (javaplugin)
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Inspect Security Manager configurationLocate java.policy or .java.security files in the JRE/lib/security directory and examine grant permissions for unsigned appletsAffected if Security Manager is disabled (security.manager.disabled=true) or policy grants socket permissions to * (allowSocketPermission *)
A user is affected if running Netscape Navigator with Java applets enabled, or any JDK/JRE version 1.0/1.1 with Java applets and an improperly configured Security Manager that permits outbound socket connections to arbitrary hosts.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade from obsolete Netscape Navigator 2.0 and JDK 1.0 to modern, supported browser and Java environments that contain proper Security Manager implementations with correct network access controls.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0142 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-1999-0142 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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