Penpot before 2.18.0 binds the MCP server plugin WebSocket bridge to all network interfaces without authentication in single-user mode. Unauthenticated attackers on adjacent networks can connect to the WebSocket port to impersonate the Penpot browser plugin, intercept task payloads, and return forged results to the MCP client.
Attack Parameters
Attack Vector
Adjacent
Requires local network access
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
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
Low
Partial disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Kaleidos Penpot
cpe:2.3:a:kaleidos:penpot:*:*:*:*:*:*:*:*
|
— |
2.18.0
|
References 6
https://github.com/penpot/penpot
disclosure@vulncheck.com
https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/…
disclosure@vulncheck.com
https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddeb
disclosure@vulncheck.com
https://github.com/penpot/penpot/security/advisories/GHSA-22qr-rp27-j9wm
disclosure@vulncheck.com
https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/penpot-before-2.18.0-unauthenticated-webso…
disclosure@vulncheck.com