Android before 4.4 does not properly arrange for seeding of the OpenSSL PRNG, which makes it easier for attackers to defeat cryptographic protection mechanisms by leveraging use of the PRNG within multiple applications.
The vold volume manager daemon on Android 3.0 and 2.x before 2.3.4 trusts messages that are received from a PFNETLINK socket, which allows local users to execute arbitrary code and gain root privileges via a negative index that bypasses a maximum-only signed integer check in the DirectVolume::handlePartitionAdded method, which triggers memory corruption, as demonstrated by Gingerbreak.