Improper parsing of octal bytes in netmask
Improper input validation of octal strings in netmask npm package v1.0.6 and below allows unauthenticated remote attackers to perform indeterminate SSRF, RFI, and LFI attacks on many of the dependent packages. A remote unauthenticated attacker can bypass packages relying on netmask to filter IPs and reach critical VPN or LAN hosts.
:exclamation: NOTE: The fix for this issue was incomplete. A subsequent fix was made in version 2.0.1 which was assigned CVE-2021-29418 / GHSA-pch5-whg9-qr2r. For complete protection from this vulnerability an upgrade to version 2.0.1 or later is recommended.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | netmask | < 1.1.0 | 1.1.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-29418
- https://github.com/rs/node-netmask/commit/3f19a056c4eb808ea4a29f234274c67bc5a848f4
- https://security.netapp.com/advisory/ntap-20210604-0001
- https://sick.codes/sick-2021-011
- https://sick.codes/universal-netmask-npm-package-used-by-270000-projects-vulnerable-to-octal-input-data-server-side-request-forgery-remote-file-inclusion-local-file-inclusion-and-more-cve-2021-28918
- https://vuln.ryotak.me/advisories/6
- https://www.npmjs.com/package/netmask
- https://nvd.nist.gov/vuln/detail/CVE-2021-28918
- https://github.com/advisories/GHSA-pch5-whg9-qr2r
- https://github.com/rs/node-netmask
- https://github.com/rs/node-netmask/blob/98294cb20695f2c6c36219a4fbcd4744fb8d0682/CHANGELOG.md#v110-mar-18-2021
- https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-011.md
- https://rootdaemon.com/2021/03/29/vulnerability-in-netmask-npm-package-affects-280000-projects
- https://security.netapp.com/advisory/ntap-20210528-0010
- https://www.bleepingcomputer.com/news/security/critical-netmask-networking-bug-impacts-thousands-of-applications
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Weakness (CWE)
CWE-20- Platform
- npm
- Package
netmask- Disclosed
- 29.03.2021
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4c7m-wxvm-r7gc - CC BY 4.0
OSV / GitHub Advisory Database - GHSA-pch5-whg9-qr2r - CC BY 4.0
Vulnerability history: netmask
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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