PRNG weakness allows for DNS poisoning on Android

Related Vulnerabilities: CVE-2015-0800   CVE-2012-2808  

Mozilla Foundation Security Advisory 2015-41

PRNG weakness allows for DNS poisoning on Android

Announced
March 31, 2015
Reporter
Daniel Stenberg
Impact
Low
Products
Firefox
Fixed in
  • Firefox 37

Description

Mozilla developer Daniel Stenberg reported that the DNS resolver in Firefox for Android uses an insufficiently random algorithm when generating random numbers for the unique identifier. This was derived from an old version of the Bionic libc library and suffered from insufficient randomness in the pseudo-random number generator (PRNG) as described by Roee Hay and Roi Saltzman.

This leaves Firefox on Android potentially vulnerable to DNS poisoning attacks because an attacker may be able to predict the identifier used, allowing for the spoofing of web sites and cookie theft.

This flaw did not affect desktop versions of Mozilla products and only Firefox for Android was affected.

References