RHSA-2025:21740 - Security Advisory

Topic

An update for bind is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The Berkeley Internet Name Domain (BIND) is an implementation of the Domain Name System (DNS) protocols. BIND includes a DNS server (named); a resolver library (routines for applications to use when interfacing with DNS); and tools for verifying that the DNS server is operating correctly.

Security Fix(es):

• bind: DNS forwarders - cache poisoning vulnerability (CVE-2021-25220)
• bind: Cache poisoning attacks with unsolicited RRs (CVE-2025-40778)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2064512 - CVE-2021-25220 bind: DNS forwarders - cache poisoning vulnerability
• BZ - 2405827 - CVE-2025-40778 bind: Cache poisoning attacks with unsolicited RRs

CVEs

• CVE-2021-25220
• CVE-2025-40778

References

• https://access.redhat.com/security/updates/classification/#important