Netis NC63 router firmware V3.0.0.3327 contains an unauthenticated firmware update vulnerability that allows unauthenticated attackers to submit unsigned firmware images by exploiting a missing authentication enforcement flaw in the Boa web server and netis.cgi CGI dispatcher. Attackers can send a multipart POST request to /cgi-bin/upload_fw.cgi without a valid session cookie, bypassing authentication because Boa grants access to any path containing '.cgi' regardless of cookie validation, and netis.cgi reads but does not enforce the authentication state before invoking the firmware update handler, which accepts images validated only by a forgeable additive checksum and static product strings rather than a cryptographic signature, potentially enabling persistent router compromise.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Public exploits 1
- ozcanpng/CVE-2026-73673 PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Change history 1
- First seenCVSS 8.7NVD modified 2026-10-24 15:10
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 5
- https://github.com/ozcanpng/CVE-2026-73673
- https://ozcanpng.dev/blog/cve-2026-73673-netis-nc63-unauthenticated-firmware-update/
- https://www.netis-systems.com/products/NC63.html
- https://www.netis-systems.com/support/downinfo.html?id=35
- https://www.vulncheck.com/advisories/netis-nc63-unauthenticated-firmware-update-with-missing-cryptographic-firmware-authentication