CVE-2025-40910
📋 TL;DR
This vulnerability in Net::IP::LPM Perl module allows attackers to bypass IP-based access controls by using IP addresses with leading zeros, which are interpreted as octal numbers. Systems using this module for IP address validation or access control lists are affected. The issue stems from improper parsing of CIDR address strings.
💻 Affected Systems
- Net::IP::LPM Perl module
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete bypass of network security controls, allowing unauthorized access to protected systems or data.
Likely Case
Partial access control bypass for specific IP ranges, potentially exposing sensitive interfaces or data.
If Mitigated
Limited impact if additional authentication layers or network segmentation exist beyond IP-based controls.
🎯 Exploit Status
Exploitation requires knowledge of IP ranges being filtered and ability to send requests from crafted IP addresses.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply patch from security advisory
Vendor Advisory: https://security.metacpan.org/patches/N/Net-IP-LPM/1.10/CVE-2025-40910-r1.patch
Restart Required: No
Instructions:
1. Download the patch from the vendor advisory URL
2. Apply patch to Net::IP::LPM installation: patch -p1 < CVE-2025-40910-r1.patch
3. Reinstall or update the Perl module: cpanm --reinstall Net::IP::LPM
🔧 Temporary Workarounds
Input validation wrapper
allAdd custom validation to strip leading zeros from IP addresses before passing to Net::IP::LPM
# Perl example: $ip =~ s/^0+//g; before calling Net::IP::LPM functions
Use alternative IP validation
allTemporarily replace Net::IP::LPM with another IP validation library
# Consider using Net::CIDR::Lite or Net::Netmask as alternatives
🧯 If You Can't Patch
- Implement network-level controls (firewall rules) as additional protection layer
- Add application-level authentication beyond IP-based controls
🔍 How to Verify
Check if Vulnerable:
Check if Net::IP::LPM version 1.10 is installed: perl -MNet::IP::LPM -e 'print $Net::IP::LPM::VERSION'Check Version:
perl -MNet::IP::LPM -e 'print "Net::IP::LPM version: $Net::IP::LPM::VERSION\n"'Verify Fix Applied:
Test IP validation with leading zeros (e.g., 010.0.0.1) - should be rejected or normalized📡 Detection & Monitoring
Log Indicators:
- Unusual IP addresses with leading zeros in access logs
- Failed access attempts from unexpected IP ranges
Network Indicators:
- Traffic from IP addresses with leading zeros in octets
- Bypass of expected IP filtering rules
SIEM Query:
source="access.log" AND (ip="0[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+" OR ip="[0-9]+\.0[0-9]+\.[0-9]+\.[0-9]+" OR ip="[0-9]+\.[0-9]+\.0[0-9]+\.[0-9]+" OR ip="[0-9]+\.[0-9]+\.[0-9]+\.0[0-9]+")