CVE-2026-76070
CriticalCVSS 9.8Summary
Netis NC63 firmware up to 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.
Risk Assessment
The risk to the organization includes full device takeover by a remote unauthenticated attacker, potentially leading to network compromise, traffic interception, or use of the device as a pivot point for further attacks.
Recommendation
It is recommended to immediately update the firmware to the latest available version that fixes this vulnerability, and to restrict administrative access to the device only from trusted networks.
Original NVD description (English source)
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.