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.