High CPU Load in DNS Message Parsing Code Affects BIND 9 Versions
CVE-2023-4408
7.5HIGH
Summary
The DNS message parsing code in the BIND 9 implementation has a section with overly high computational complexity, which is not problematic under standard DNS traffic but can result in excessive CPU load. This vulnerability can be exploited through specially crafted DNS queries and responses, affecting both authoritative servers and recursive resolvers. Users of BIND 9 who run versions from 9.0.0 to 9.16.45, 9.18.0 to 9.18.21, 9.19.0 to 9.19.19, and various S1 versions, should take precautions to mitigate potential impact.
Affected Version(s)
BIND 9 9.0.0 <= 9.16.45
BIND 9 9.18.0 <= 9.18.21
BIND 9 9.19.0 <= 9.19.19
References
CVSS V3.1
Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged
Timeline
- 👾
Exploit known to exist
Vulnerability published
Vulnerability Reserved
Credit
ISC would like to thank Shoham Danino from Reichman University, Anat Bremler-Barr from Tel-Aviv University, Yehuda Afek from Tel-Aviv University, and Yuval Shavitt from Tel-Aviv University for bringing this vulnerability to our attention.