Description
A certain pseudo-random number generator (PRNG) algorithm that uses XOR and 3-bit random hops (aka "Algorithm X3"), as used in OpenBSD 2.8 through 4.2, allows remote attackers to guess sensitive values such as DNS transaction IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as DNS cache poisoning against OpenBSD's modification of BIND.
References
- 20080206 A paper by Amit Klein (Trusteer): "OpenBSD DNS Cache Poisoning and Multiple O/S Predictable IP ID Vulnerability" mailing-list
- 28819 third-party-advisory
- http://www.trusteer.com/docs/OpenBSD_DNS_Cache_Poisoning_and_Multiple_OS_Predictable_IP_ID_Vulnerability.pdf
- http://www.securiteam.com/securityreviews/5PP0H0UNGW.html
- openbsd-prng-dns-spoofing(40329) vdb-entry
- 27647 vdb-entry