#VU61422 Reliance on Reverse DNS Resolution for a Security-Critical Action in ISC BIND - CVE-2021-25220
Published: March 17, 2022 / Updated: October 30, 2023
Vulnerability identifier: #VU61422
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N/E:U/U:Green
CVE-ID: CVE-2021-25220
CWE-ID: CWE-350
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
ISC BIND
ISC BIND
Software vendor:
ISC
ISC
Description
The vulnerability allows a remote attacker to poison DNS cache.
The vulnerability exists due to an error in DNS forwarder implementation. When using forwarders, bogus NS records supplied by, or via, those forwarders may be cached and used by named if it needs to recurse for any reason, causing it to obtain and pass on potentially incorrect answers. The cache could become poisoned with incorrect records leading to
queries being made to the wrong servers, which might also result in
false information being returned to clients.
Remediation
Install updates from vendor's website.