isc bind CVE-2021-25219 vulnerability in ISC and Other Products
Published on October 27, 2021

Lame cache can be abused to severely degrade resolver performance

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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.

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Vulnerability Analysis

CVE-2021-25219 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
LOW

Products Associated with CVE-2021-25219

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2021-25219 are published in these products:

ISC BIND
 
Debian Linux
 
Fedora Project Fedora
 
NetApp Cloud Backup
 
Siemens Sinec Infrastructure Network Services
 
Oracle Http Server
 
Oracle Zfs Storage Appliance Kit
 

Affected Versions

ISC BIND9:

Exploit Probability

EPSS
0.71%
Percentile
71.87%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.