CVE-2021-29418

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-03-30 · updated 2026-06-17
Weakness: CWE-20

Description

The netmask package before 2.0.1 for Node.js mishandles certain unexpected characters in an IP address string, such as an octal digit of 9. This (in some situations) allows attackers to bypass access control that is based on IP addresses. NOTE: this issue exists because of an incomplete fix for CVE-2021-28918.

Affected products

Netmask Project Netmask: before 2.0.1 — fixed in 2.0.1

How to fix

Upgrade to a fixed version: Netmask Project Netmask 2.0.1. Check the vendor advisory for mitigations.

References

https://github.com/rs/node-netmask/commit/3f19a056c4eb808ea4a29f234274c67bc5a848f4
https://security.netapp.com/advisory/ntap-20210604-0001/
https://vuln.ryotak.me/advisories/6
https://github.com/rs/node-netmask/commit/3f19a056c4eb808ea4a29f234274c67bc5a848f4
https://security.netapp.com/advisory/ntap-20210604-0001/
https://vuln.ryotak.me/advisories/6

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