CVE-2026-75492

Description

Cudy TR3000 before 2.5.42 contains an unauthenticated stack buffer overflow vulnerability in the stun_client TR-111 UDP Connection Request parser that parses requests before verifying username or HMAC. Remote attackers can send a single crafted UDP datagram lacking a space in the request line, causing strncpy() to overflow a 10-byte stack buffer and crash stun_client for denial of service.

References

• https://d1jvyy13vm72kv.cloudfront.net/device/upgrade/m_upgrade_TR3000_256MB_Flash-R103-2.5.42-20261103-160202-sysupgrade_82672.zip
• https://www.cudy.com/en-us/pages/download-center/tr3000-1-0
• https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-stack-buffer-overflow-via-stun-client-udp-parser