CVE-2026-73673 (GCVE-0-2026-73673)
Vulnerability from cvelistv5 – Published: 2026-08-14 12:21 – Updated: 2026-08-19 20:09
VLAI
EPSS
VEX
Title
Netis NC63 V3.0.0.3327 Unauthenticated Firmware Update with Missing Cryptographic Firmware Authentication
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-14 14:40 UTC
CWE
- CWE-306 - Missing Authentication for Critical Function
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://www.netis-systems.com/products/NC63.html | issue-tracking |
| https://ozcanpng.dev/blog/cve-2026-73673-netis-nc… | technical-description |
| https://github.com/ozcanpng/CVE-2026-73673 | technical-description |
| https://www.vulncheck.com/advisories/netis-nc63-u… | third-party-advisory |
| https://www.netis-systems.com/support/downinfo.ht… | product |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Netis Systems Co., Ltd. | Netis NC63 Wireless AC1200 Router |
Affected:
0 , ≤ V3.0.0.3327
(custom)
|
guessed |
Date Public
2026-08-14 00:00
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