PerlApplication · Larry Wall
CVE-2003-0900
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 · uneditedPerl 5.8.1 on Fedora Core does not properly initialize the random number generator when forking, which makes it easier for attackers to predict random numbers.
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 confidencePerl 5.8.1 on Fedora Core fails to reinitialize the random number generator when the process forks, causing child processes to inherit the same RNG state as the parent. This makes random numbers predictable across forked processes, enabling attacks on applications using rand() for security-sensitive purposes like session tokens or cryptographic seeding.
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
PerlApplication
= 5.8.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check installed Perl versionRun 'perl -v' or 'perl --version' and look for the version number in the outputAffected if The version listed is exactly 5.8.1
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Verify Fedora Core or derivativeRun 'cat /etc/fedora-release' or 'cat /etc/redhat-release' to identify the Linux distributionAffected if The system is running Fedora Core (any version) or a derivative that ships Perl 5.8.1 as the default
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Identify if application uses fork()Search application source code for 'fork' function calls using 'grep -r "fork"' or code reviewAffected if The application calls fork() to create child processes
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Check if rand() is used for security-sensitive operationsSearch for 'rand()' usage in code related to session tokens, cryptographic seeding, or other security functionsAffected if rand() is called after fork() for generating session IDs, tokens, keys, or other security-critical values
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Verify srand() is not called after fork()Review code to confirm whether srand() is invoked immediately after fork() in child processes to reseed the RNGAffected if No srand() call exists in the child process after fork(), meaning RNG state is inherited from parent
You are affected if running Perl 5.8.1 on Fedora Core and your application uses fork() followed by rand() for security purposes without calling srand() to reseed in child processes.
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 to a patched Perl version or explicitly call srand() with fresh entropy in child processes after fork() to reseed the random number generator.
Fix this in Perl
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2003-0900 — 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-2003-0900 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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- Version or environment caveats, and links to real fixes
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