Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths.

What happened

Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths. Non-numeric and non-ASCII prefix lengths are accepted and treated as 0. Integers over 31 bits are silently truncated. A single malformed mask will poison the lookup table. The result is that the lookup will silently succeed for every address. An allow-list will allow every address, and a deny-list will block every address.

Affected versions

Unknown product: before 1.12 (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.