Skip to content
Fencer Vulns
medium 5.3

CVE-2021-29418 json

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.

published 2021-03-30 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-0690

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

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.

Patch / fix

  • netmask_project netmask 2.0.1

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-2021-29418 updated cvss 5.3

nodejs-netmask: incorrectly parses an IP address that has octal integer with invalid character

  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/grc-ui-rhel8, rhacm2/mcm-topology-rhel8, rhacm2/application-ui-rhel8
    affected: no fix available “Fix deferred”
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-header-rhel8
    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

Exploit prediction

1.51% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

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.