CVE-2023-31127

libspdm is a sample implementation that follows the DMTF SPDM specifications. A vulnerability has been identified in SPDM session establishment in libspdm prior to version 2.3.1. If a device supports both DHE session and PSK session with mutual<br /> authentication, the attacker may be able to establish the session with `KEY_EXCHANGE` and `PSK_FINISH` to bypass the mutual authentication. This is most likely to happen when the Requester begins a session using one method (DHE, for example) and then uses the other method&amp;#39;s finish (PSK_FINISH in this example) to establish the session. The session hashes would be expected to fail in this case, but the condition was not detected.<br /> <br /> This issue only impacts the SPDM responder, which supports `KEY_EX_CAP=1 and `PSK_CAP=10b` at same time with mutual authentication requirement. The SPDM requester is not impacted. The SPDM responder is not impacted if `KEY_EX_CAP=0` or `PSK_CAP=0` or `PSK_CAP=01b`. The SPDM responder is not impacted if mutual authentication is not required.<br /> <br /> libspdm 1.0, 2.0, 2.1, 2.2, 2.3 are all impacted. Older branches are not maintained, but users of the 2.3 branch may receive a patch in version 2.3.2. The SPDM specification (DSP0274) does not contain this vulnerability.