MCPHub before 1.0.32 contains an authentication bypass vulnerability in its embedded OAuth 2.0 authorization server where client authentication is disabled by default and PKCE enforcement is optional. Attackers who obtain an authorization code through interception can redeem it for access tokens without providing a client secret or PKCE verifier, gaining access to victim accounts and their privileges.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 5
https://github.com/samanhappy/mcphub/blob/v1.0.31/src/services/oauthServerServi…
disclosure@vulncheck.com
https://github.com/samanhappy/mcphub/commit/e927620cd1a80e8691213b01eb8cd6ffa1a…
disclosure@vulncheck.com
https://github.com/samanhappy/mcphub/releases/tag/v1.0.32
disclosure@vulncheck.com
https://github.com/samanhappy/mcphub/security/advisories/GHSA-3m7m-37xf-xp9x
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/mcphub-before-1.0.32-oauth-2.0-authenticat…
disclosure@vulncheck.com