CVE-2022-4874 — Authentication bypass in Netcomm router models NF20MESH, NF20, and NL1902 allows

Authentication bypass in Netcomm router models NF20MESH, NF20, and NL1902 allows an unauthenticated user to access content. In order to serve static content, the application performs a check for the existence of specific characters in the URL (.css, .png etc). If it exists, it pe

01What is this vulnerability?

Authentication bypass in Netcomm router models NF20MESH, NF20, and NL1902 allows an unauthenticated user to access content. In order to serve static content, the application performs a check for the existence of specific characters in the URL (.css, .png etc). If it exists, it performs a "fake login" to give the request an active session to load the file and not redirect to the login page.

02Affected products

Vendor	Product	Versions
Netcomm	NF20	R6B025
Netcomm	NF20MESH	R6B025
Netcomm	NL1902	R6B025

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-01-11T20:39:25.219Z
• Last modified: 2025-11-04T19:14:31.884Z

09References

• github.com — https://github.com/scarvell/advisories/blob/main/2022_netcomm_nf20mesh_unauth_rc…