Bug 2528764 (CVE-2026-57165)

Summary: CVE-2026-57165 pjsip: pre-authentication overflow in the telnet CLI history
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in PJSIP. A stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when redrawing the command line during history recall. A remote attacker, with access to the unauthenticated telnet CLI, can trigger this issue because the line-redraw sequence can accumulate more data than a fixed-size stack buffer can hold. This can cause an application termination, leading to a Denial of Service (DoS). This vulnerability only affects applications that have the telnet CLI front-end enabled.
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Bug Depends On: 2531098, 2531099, 2531100, 2531101    
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Description OSIDB Bzimport 2026-09-04 17:28:24 UTC 
PJSIP is a free and open source multimedia communication library written in C. Prior to commit 628b716, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when redrawing the command line during history recall (handle_up_down() in cli_telnet.c). This affects only applications that enable the telnet CLI front-end (same gating as the related CLI issue). The line-redraw sequence for a recalled history entry can accumulate more data than a fixed-size stack buffer holds, which may lead to application termination. Exploitation requires access to the unauthenticated telnet CLI, which already permits arbitrary CLI commands, so the additional impact is limited. Applications that do not enable the telnet CLI front-end are not affected. This issue has been patched via commit 628b716.