CVE-2013-1437
📋 TL;DR
This CVE describes an eval injection vulnerability in Perl's Module-Metadata module that allows remote attackers to execute arbitrary Perl code by manipulating the $Version value. This affects systems using vulnerable versions of the Module-Metadata module before 1.000015. The vulnerability enables remote code execution with potentially severe consequences.
💻 Affected Systems
- Perl Module-Metadata
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Module Metadata by Module Metadata Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the affected system, allowing data theft, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to application compromise, data exfiltration, and potential privilege escalation on the affected host.
If Mitigated
Limited impact with proper input validation and sandboxing, potentially reduced to denial of service or information disclosure.
🎯 Exploit Status
The vulnerability is straightforward to exploit as it involves direct eval injection with user-controlled input.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.000015 and later
Vendor Advisory: https://metacpan.org/changes/distribution/Module-Metadata
Restart Required: No
Instructions:
1. Update Perl Module-Metadata to version 1.000015 or later using CPAN: 'cpan Module-Metadata'
2. Verify the update with: 'perl -MModule::Metadata -e "print $Module::Metadata::VERSION"'
3. Restart any Perl applications or services using the module.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation to reject or sanitize any untrusted input passed to Module-Metadata parsing functions.
# Implement input validation in Perl code before calling Module::Metadata functions
# Example: validate $version input before processing
if ($version !~ /^[\d\.]+$/) { die "Invalid version format"; }
🧯 If You Can't Patch
- Implement network segmentation to isolate systems using vulnerable Module-Metadata versions from untrusted networks.
- Deploy application-level firewalls or WAF rules to block suspicious patterns in input to Perl applications.
🔍 How to Verify
Check if Vulnerable:
Check the installed Module-Metadata version with: perl -MModule::Metadata -e "print $Module::Metadata::VERSION"Check Version:
perl -MModule::Metadata -e "print $Module::Metadata::VERSION"Verify Fix Applied:
Verify version is 1.000015 or higher with: perl -MModule::Metadata -e "print $Module::Metadata::VERSION >= 1.000015 ? 'PATCHED' : 'VULNERABLE'"📡 Detection & Monitoring
Log Indicators:
- Unusual Perl eval errors in application logs
- Suspicious process execution from Perl applications
- Unexpected network connections from Perl processes
Network Indicators:
- Outbound connections from Perl applications to unexpected destinations
- Unusual HTTP/HTTPS traffic patterns from Perl services
SIEM Query:
source="*perl*" AND (eval OR "Module::Metadata" OR "arbitrary code")🔗 References
- http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114904.html
- http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114912.html
- https://metacpan.org/changes/distribution/Module-Metadata
- http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114904.html
- http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114912.html
- https://metacpan.org/changes/distribution/Module-Metadata
