CVE-2021-25215

An assertion check can fail while answering queries for DNAME records that require the DNAME to be processed to resolve itself

Description

In BIND 9.0.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.9.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.11 of the BIND 9.17 development branch, when a vulnerable version of named receives a query for a record triggering the flaw described above, the named process will terminate due to a failed assertion check. The vulnerability affects all currently maintained BIND 9 branches (9.11, 9.11-S, 9.16, 9.16-S, 9.17) as well as all other versions of BIND 9.

Remediation

Solution:

  • Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.31 BIND 9.16.15 BIND 9.17.12 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.31-S1 BIND 9.16.15-S1

Workaround:

  • No workarounds known.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 2.32% Top 20%
Vendor Advisory debian.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory isc.org
Affected: ISC BIND9
Published at:
Updated at:

References

Link Tags
https://kb.isc.org/v1/docs/cve-2021-25215 vendor advisory
http://www.openwall.com/lists/oss-security/2021/04/29/1 third party advisory mailing list
http://www.openwall.com/lists/oss-security/2021/04/29/2 third party advisory mailing list
http://www.openwall.com/lists/oss-security/2021/04/29/3 third party advisory mailing list
http://www.openwall.com/lists/oss-security/2021/04/29/4 third party advisory mailing list
https://www.debian.org/security/2021/dsa-4909 third party advisory vendor advisory
https://lists.debian.org/debian-lts-announce/2021/05/msg00001.html third party advisory mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VEC2XG4Q2ODTN2C4CGXEIXU3EUTBMK7L/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDSRPCJQ7MZC6CENH5PO3VQOFI7VSWBE/ vendor advisory
https://www.oracle.com/security-alerts/cpuoct2021.html third party advisory patch
https://security.netapp.com/advisory/ntap-20210521-0006/ third party advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-25215?
CVE-2021-25215 has been scored as a high severity vulnerability.
How to fix CVE-2021-25215?
To fix CVE-2021-25215: Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.31 BIND 9.16.15 BIND 9.17.12 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.31-S1 BIND 9.16.15-S1
Is CVE-2021-25215 being actively exploited in the wild?
It is possible that CVE-2021-25215 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-25215?
CVE-2021-25215 affects ISC BIND9.
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