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Dear LIVE555 Maintainers,</div>
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I am writing to report a potential security vulnerability I discovered in the<br>
LIVE555 Streaming Media library.</div>
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Summary<br>
A potential high-severity RTSP session hijacking issue exists in the RTSP<br>
server session handling logic.<br>
For in-session commands (e.g., PLAY, PAUSE, TEARDOWN, GET_PARAMETER,<br>
SET_PARAMETER), the server appears to rely on the Session identifier as a<br>
bearer token and does not enforce re-authentication (or session-binding<br>
checks) on that path.<br>
If an attacker obtains a valid Session ID, they may be able to control or<br>
terminate another client’s RTSP session from a separate connection.</div>
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Affected Version</div>
<ul>
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Version: live.2026.04.01 (official release from download.live555.com)</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Component: liveMedia RTSP server session handling (RTSPServer.cpp)</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Discovery date: 2026-04-22</li></ul>
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Vulnerability Details<br>
Observed code path in liveMedia/RTSPServer.cpp (official source):</div>
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Session lookup and reuse: </li><ul>
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
RTSPServer.cpp:819</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
RTSPServer.cpp:821</li></ul>
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In-session commands dispatched directly: </li><ul>
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
RTSPServer.cpp:891</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
RTSPServer.cpp:897</li></ul>
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In-session handler entry (no mandatory re-authentication observed on this<br>
path): </li><ul>
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RTSPServer.cpp:1682</li></ul>
</ul>
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Potential root cause: Authentication is enforced during earlier phases (such<br>
as DESCRIBE/SETUP), but in-session command handling does not appear to require<br>
renewed authentication or strong binding of Session to the original<br>
authenticated connection context.</div>
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Steps to Reproduce (locally verified)</div>
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<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Build and run testOnDemandRTSPServer with ACCESS_CONTROL enabled.</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Use valid credentials (username1/password1) to complete Digest auth and<br>
send SETUP.</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Observe server accepts the request and the original client session is<br>
invalidated.</li></ol>
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Reproduction Evidence (excerpt)</div>
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STEP3 status: RTSP/1.0 200 OK</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
SESSION=70C812EF</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
ATTACK status: RTSP/1.0 200 OK</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
VERIFY status: RTSP/1.0 454 Session Not Found</li></ul>
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Impact</div>
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<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Integrity: Unauthorized session control commands can be issued.</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Availability: Attackers can disrupt service by forcing TEARDOWN/PAUSE.</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Prerequisite: Attacker needs a valid session ID (e.g., obtained via<br>
plaintext RTSP sniffing, logs, proxy visibility, or other leakage vectors).</li></ul>
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Potential Classification</div>
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CWE candidates: </li><ul>
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CWE-306 (Missing Authentication for Critical Function)</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
CWE-639 (Authorization Bypass Through User-Controlled Key)</li></ul>
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CVSS draft vector (for your review): </li><ul>
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AV:N / AC:L / PR:N / UI:N / S:U / C:L / I:H / A:H</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<div role="presentation">Likely high severity range.</div>
</li></ul>
</ul>
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Suggested Fix</div>
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Enforce authentication (or equivalent authorization checks) for in-session<br>
commands:<br>
PLAY/PAUSE/TEARDOWN/GET_PARAMETER/SET_PARAMETER.</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Bind session usage to original authenticated context (e.g., connection/<br>
source/IP/token binding).</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<div class="elementToProof" role="presentation">Add regression tests:</div>
<div role="presentation">After a legitimate session is established, unauthenticated TEARDOWN from<br>
a second connection must fail (401/454) and must not terminate the original session.</div>
</li></ol>
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Best regards,<br>
CUI Jiyuan<br>
<a href="mailto:cui13969607249@outlook.com" target="_blank" id="OWAba138481-27b5-b837-72bf-e37863228347" class="external-link OWAAutoLink" rel="noopener nofollow" data-tooltip-position="top">cui13969607249@outlook.com</a></div>
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