CVE-2022-2795: Processing large delegations may severely degrade resolver performance
Document version: 2.0
Posting date: 21 September 2022
Program impacted: BIND
- 9.0.0 -> 9.16.32
- 9.18.0 -> 9.18.6
- 9.19.0 -> 9.19.4
BIND Supported Preview Edition
- 9.9.3-S1 -> 9.11.37-S1
- 9.16.8-S1 -> 9.16.32-S1
A flaw in resolver code can cause
named to spend excessive amounts of time on processing large delegations.
By flooding the target resolver with queries exploiting this flaw an attacker can significantly impair the resolver's performance, effectively denying legitimate clients access to the DNS resolution service.
CVSS Score: 5.3
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L&version=3.1.
No workarounds known.
We are not aware of any active exploits.
Upgrade to the patched release most closely related to your current version of BIND:
BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers.
ISC would like to thank Yehuda Afek from Tel-Aviv University and Anat Bremler-Barr & Shani Stajnrod from Reichman University for bringing this vulnerability to our attention.
Document revision history:
1.0 Early Notification, 14 September 2022
1.1 Minor punctuation corrections, 19 September 2022
2.0 Public disclosure, 21 September 2022
See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected.
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ISC patches only currently supported versions. When possible we indicate EOL versions affected. For current information on which versions are actively supported, please see https://www.isc.org/download/.
ISC Security Vulnerability Disclosure Policy:
Details of our current security advisory policy and practice can be found in the ISC Software Defect and Security Vulnerability Disclosure Policy at https://kb.isc.org/docs/aa-00861.
The Knowledgebase article https://kb.isc.org/docs/cve-2022-2795 is the complete and official security advisory document.
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