Bug 2569561 (CVE-2026-125406)

Summary: CVE-2026-125406 ettercap: ettercap: Arbitrary code execution via Telnet dissector backspace handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in ettercap. This vulnerability allows an attacker on the local network to achieve arbitrary code execution or cause a Denial of Service (DoS). The Telnet protocol dissector fails to validate memory boundaries when processing backspace characters, allowing an out-of-bounds write to stack memory. By transmitting a network stream with excessive backspace characters, an attacker can corrupt process memory and potentially compromise the ettercap application.
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Description OSIDB Bzimport 2026-11-10 13:03:50 UTC 
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.