Executive brief
ISC BIND is a widely used system for translating human-readable website names into IP addresses. A flaw in older versions allows attackers to redirect internet traffic to malicious servers by providing false information that the system then stores in its memory. This can lead to users being sent to fraudulent websites or having their email intercepted without their knowledge.
Technical details
The vulnerability exists in ISC BIND due to the use of predictable transaction IDs (TXIDs) in DNS queries. An unauthenticated remote attacker can exploit this by predicting the next query ID and sending a forged DNS response to a recursive nameserver before the legitimate response arrives. If successful, the forged response is cached by the server, leading to DNS cache poisoning. This allows the attacker to spoof DNS records and redirect traffic for affected domains. The issue is a classic example of insufficient entropy in protocol identifiers.
Affected products
- ISC BIND
Timeline
- 1997-08-13: disclosed: Initial publication date