Twenty is an open source CRM. Prior to version 1.18, the SSRF protection in SecureHttpClientService validated request URLs at the request level but did not validate redirect targets. An authenticated user who could control outbound request URLs (e.g., webhook endpoints, image URLs) could bypass private IP blocking by redirecting through an attacker-controlled server.
This issue has been patched in version 1.18.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v3.1