Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the restore_existing_session path to assume a victim's permissions and roles, enabling unauthorized invocation of tools and access to data restricted to the authenticated victim.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea9796760…
disclosure@vulncheck.com
https://github.com/Chainlit/chainlit/pull/2857
disclosure@vulncheck.com
https://github.com/Chainlit/chainlit/releases/tag/2.10.1
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-s…
disclosure@vulncheck.com