WebAPI/Security/WebTelephony

Name of API: Web Telephony References: https://wiki.mozilla.org/WebAPI/WebTelephony

Brief purpose of API: Make and receive phone calls

General Use Cases: None

Inherent threats:

  • Place calls to high cost numbers,
  • Route calls through high cost network,
  • Direct calls through MITM network (spying).
  • Possibly with audio API, record phone calls, record touch tone signals (account numbers?).
  • In addition, there is a high likelihood that this API will need to be controlled for legal reasons.

Threat severity: high to critical, confidential information disclosure and direct financial risk

Regular web content (unauthenticated)

Use cases for unauthenticated code: click on a phone number in an email or browser to dial Authorization model for uninstalled web content: explicit (web activities) Authorization model for installed web content: explicit (web activities) Potential mitigations: When user clicks on a phone number, app triggers a web activity to initiate the call. User interaction required to trigger.

Trusted (authenticated by publisher)

Use cases for authenticated code:

  • Fun dialers (eg. rotary dialer)

Authorization model: explicit (web activities)

Certified (vouched for by trusted 3rd party)

Use cases for certified code:

  • Handler for telephony web activities
  • Replacement dialer
  • Voice conference software (e.g. connect Voip with a mobile call)?
  • Mediate incoming calls (accept/reject/merge)
  • Query transceiver state

Authorization model: implicit Potential mitigations: none