Chainlit through 2.12.0 fails to validate the client-supplied socket.io sessionId parameter, allowing unauthenticated attackers to traverse filesystem paths by injecting absolute or relative path sequences. Attackers can craft malicious sessionId values that escape the upload directory and recursively delete arbitrary directories accessible to the service process.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 5
https://github.com/Chainlit/chainlit
disclosure@vulncheck.com
https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/session.py
disclosure@vulncheck.com
https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/socket.py
disclosure@vulncheck.com
https://pypi.org/project/chainlit/
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/chainlit-through-2.12.0-path-traversal-via…
disclosure@vulncheck.com