CVE-2026-125406

Description

Ettercap through 0.8.4.1 contains a stack buffer underwrite vulnerability in the telnet dissector in src/dissectors/ec_telnet.c that decrements the output pointer on backspace without a lower bound check. Attackers can send a telnet stream with more backspaces than preceding characters to write below the stack buffer, corrupting the stack of the Ettercap process that normally runs as root.

References

• https://github.com/Ettercap/ettercap/blob/v0.8.4.1/src/dissectors/ec_telnet.c#L150-L159
• https://github.com/Ettercap/ettercap/commit/1d8badb713579419a29a494bb463a1af59707e98
• https://github.com/Ettercap/ettercap/pull/1330
• https://github.com/Ettercap/ettercap/security/advisories/GHSA-w5ch-7c4x-crcc
• https://www.vulncheck.com/advisories/ettercap-through-0.8.4.1-stack-buffer-underwrite-via-telnet-dissector-backspace-handling