Description
The Net::Netmask module before 2.0000 for Perl does not properly consider extraneous zero characters at the beginning of an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libnet-netmask-perl | 1.9104-2 | — |
| Debian 13 | libnet-netmask-perl | 1.9104-2 | — |
| Debian 12 | libnet-netmask-perl | 1.9104-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libnetwork-ipv4addr-perl | No fix yet | — |
| Ubuntu 26.04 LTS | libnetwork-ipv4addr-perl | No fix yet | — |
| Ubuntu 25.10 | libnetwork-ipv4addr-perl | No fix yet | — |
| Ubuntu 24.04 LTS | libnetwork-ipv4addr-perl | No fix yet | — |
| Ubuntu 22.04 LTS | libnetwork-ipv4addr-perl | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libnet-netmask-perl +1 | No fix yet | — |
| Ubuntu 18.04 LTS | libnet-netmask-perl +1 | No fix yet | — |
| Ubuntu 16.04 LTS | libnet-netmask-perl +1 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP5 | perl-Net-Netmask | 1.9022-bp155.3.3.1 | openSUSE-SU-2023:0217-1 |
| SUSE Package Hub 15 SP4 | perl-Net-Netmask | 1.9022-bp154.2.3.1 | openSUSE-SU-2023:0215-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.5 | perl-Net-Netmask | 1.9022-bp155.3.3.1 | openSUSE-SU-2023:0217-1 |
| openSUSE Leap 15.4 | perl-Net-Netmask | 1.9022-bp154.2.3.1 | openSUSE-SU-2023:0215-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | perl-net-netmask | 2.0000-r0 | — |
Advisories 2
- openSUSE-SU-2023:0217-1 Security update for perl-Net-Netmask SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2023:0215-1 Security update for perl-Net-Netmask SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://blog.urth.org/2021/03/29/security-issues-in-perl-ip-address-distros/
- https://metacpan.org/changes/distribution/Net-Netmask#L11-22
- FEDORA-2021-3d96cfe6a3 vendor-advisory
- FEDORA-2021-be62be8c7c vendor-advisory
- FEDORA-2021-c314017fcc vendor-advisory
- https://security.netapp.com/advisory/ntap-20210604-0007/