The Twilio integration webhook handler accepts any POST request without validating Twilio's 'X-Twilio-Signature'.
When processing media messages, it fetches user-controlled URLs ('MediaUrlN' parameters) using HTTP requests that include the integration's Twilio credentials in the 'Authorization' header.
An attacker can forge a webhook payload pointing to their own server and receive the victim's 'accountSID' and 'authToken' in plaintext (base64-encoded Basic Auth), leading to full compromise of the Twilio account.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:HI:LA:N8.2/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N