CVEvulnerability
CVE-2026-73673
8.7 HIGH
Official page ↗
- Status
- Deferred
- Published
- 2026-08-14
- Last modified
- 2026-10-24
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 8.7 HIGH — CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 8.8 HIGH — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-306
Description
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.
Related
Weakness · CWE (1)
- CWE-306 Missing Authentication for Critical Functionality weakness
References
- https://github.com/ozcanpng/CVE-2026-73673 github.com
- https://ozcanpng.dev/blog/cve-2026-73673-netis-nc63-unauthenticated-firmware-update/ ozcanpng.dev
- https://www.netis-systems.com/products/NC63.html www.netis-systems.com
- https://www.netis-systems.com/support/downinfo.html?id=35 www.netis-systems.com
- https://www.vulncheck.com/advisories/netis-nc63-unauthenticated-firmware-update-with-missing-cryptographic-firmware-authentication www.vulncheck.com