Lame cache can be abused to severely degrade resolver performance

CVE-2021-25219

5.3MEDIUM

Key Information

Vendor
Isc
Status
Bind9
Vendor
CVE Published:
27 October 2021

Badges

👾 Exploit Exists

Summary

In BIND 9.3.0 -> 9.11.35, 9.12.0 -> 9.16.21, and versions 9.9.3-S1 -> 9.11.35-S1 and 9.16.8-S1 -> 9.16.21-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.18 of the BIND 9.17 development branch, exploitation of broken authoritative servers using a flaw in response processing can cause degradation in BIND resolver performance. The way the lame cache is currently designed makes it possible for its internal data structures to grow almost infinitely, which may cause significant delays in client query processing.

Affected Version(s)

BIND9 Open Source Branches 9.3 through 9.11 9.3.0 through versions before 9.11.36

BIND9 Open Source Branches 9.12 through 9.16 9.12.0 through versions before 9.16.22

BIND9 Supported Preview Branches 9.9-S through 9.11-S 9.9.3-S1 through versions before 9.11.36-S1

References

https://kb.isc.org/v1/docs/cve-2021-25219
https://www.debian.org/security/2021/dsa-4994
vendor-advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg0...
mailing-list

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Collectors

NVD DatabaseMitre Database

Credit

ISC would like to thank Kishore Kumar Kothapalli of Infoblox for bringing this vulnerability to our attention.
.