CVE-2021-25220

DNS forwarders - cache poisoning vulnerability

Description

BIND 9.11.0 -> 9.11.36 9.12.0 -> 9.16.26 9.17.0 -> 9.18.0 BIND Supported Preview Editions: 9.11.4-S1 -> 9.11.36-S1 9.16.8-S1 -> 9.16.26-S1 Versions of BIND 9 earlier than those shown - back to 9.1.0, including Supported Preview Editions - are also believed to be affected but have not been tested as they are EOL. 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

Solution:

  • Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.37 BIND 9.16.27 BIND 9.18.1 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.37-S1 BIND 9.16.27-S1

Workaround:

  • If applicable, modify your configuration to either remove all forwarding or all possibility of recursion. Depending on your use-case, it may be possible to use other zone types to replace forward zones. Active exploits: We are not aware of any active exploits.

Category

6.8
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.08%
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org Vendor Advisory isc.org
Affected: ISC BIND
Published at:
Updated at:

References

Link Tags
https://kb.isc.org/v1/docs/cve-2021-25220 mitigation vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYD7US4HZRFUGAJ66ZTHFBYVP5N3OQBY/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/API7U5E7SX7BAAVFNW366FFJGD6NZZKV/ vendor advisory
https://security.netapp.com/advisory/ntap-20220408-0001/ third party advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5VX3I2U3ICOIEI5Y7OYA6CHOLFMNH3YQ/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2SXT7247QTKNBQ67MNRGZD23ADXU6E5U/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DE3UAVCPUMAKG27ZL5YXSP2C3RIOW3JZ/ vendor advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdf third party advisory patch
https://security.gentoo.org/glsa/202210-25 third party advisory vendor advisory
https://supportportal.juniper.net/s/article/2022-10-Security-Bulletin-Junos-OS-SRX-Series-Cache-poisoning-vulnerability-in-BIND-used-by-DNS-Proxy-CVE-2021-25220?language=en_US

Frequently Asked Questions

What is the severity of CVE-2021-25220?
CVE-2021-25220 has been scored as a medium severity vulnerability.
How to fix CVE-2021-25220?
To fix CVE-2021-25220: Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.37 BIND 9.16.27 BIND 9.18.1 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.37-S1 BIND 9.16.27-S1
Is CVE-2021-25220 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-25220 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-25220?
CVE-2021-25220 affects ISC BIND.
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