Description
Netis NC63 firmware through V3.0.0.3327 contains a stack-based buffer overflow vulnerability that allows unauthenticated remote attackers to overwrite saved stack state by submitting an oversized Base64-encoded password to the login handler in /bin/netis.cgi. Attackers can exploit the custom Base64 decoder's lack of output length validation against the fixed-size stack buffer to achieve remote code execution with root privileges, as the Boa web server executes the CGI environment as root.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Netis Systems | NC63 | ≤ 3.0.0.3327 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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ozcanpng/CVE-2026-76070 ★ 1 · Aug 19, 2026
Original research and PoC for a pre-auth Base64-decoded password stack buffer overflow in Netis NC63 login.cgi
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- Researcher Blog technical-description exploit
- Researcher GitHub Repo technical-description exploit
- Product Page product
- https://www.vulncheck.com/advisories/netis-nc63-stack-buffer-overflow-via-login-password-parameter third-party-advisory