The Net::IPV4Addr module 0.10 for Perl does not properly consider extraneous zero characters in an IP address string, which (in some situat…

published 2024-03-18 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33803

cvss: 9.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits: 0; none known

The Net::IPV4Addr module 0.10 for Perl does not properly consider extraneous zero characters in an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-47155 updated 2026-03-27 cvss 6.3

Net-IPv4Addr: improper handling of extraneous zero characters in an IP address string

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 2 y ago (2024-08-29)

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA	3.1	9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

perl perl

Classification

Weakness

CWE-284 Improper Access Control

References

Sources

CVE List CVE-2021-47155
NVD CVE-2021-47155

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary