CVE-2021-25219

Name: CVE-2021-25219
Creator: NVD / NIST
Published: 2021-10-27T21:15:07.613+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 8.00%

Last modified Jun 17, 2026

CVE-2021-25219 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. EPSS estimates a 8.00% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

8.00%

94.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Isc	Bind	>= 9.3.0, < 9.11.36	—
Isc	Bind	>= 9.12.0, < 9.16.22	—
Isc	Bind	>= 9.17.0, < 9.17.19	—
Isc	Bind	9.9.3	S1
Isc	Bind	9.9.12	S1
Isc	Bind	9.9.13	S1
Isc	Bind	9.10.5	S1
Isc	Bind	9.10.7	S1
Isc	Bind	9.11.3	S1
Isc	Bind	9.11.5	S3
Isc	Bind	9.11.6	S1
Isc	Bind	9.11.7	S1
Isc	Bind	9.11.8	S1
Isc	Bind	9.11.12	S1
Isc	Bind	9.11.21	S1
Isc	Bind	9.11.27	S1
Isc	Bind	9.11.29	S1
Isc	Bind	9.11.35	S1
Isc	Bind	9.16.8	S1
Isc	Bind	9.16.11	S1
Isc	Bind	9.16.13	S1
Isc	Bind	9.16.21	S1
Debian	Debian Linux	9.0	—
Debian	Debian Linux	10.0	—
Debian	Debian Linux	11.0	—
Fedoraproject	Fedora	33	—
Fedoraproject	Fedora	34	—
Fedoraproject	Fedora	35	—
Netapp	H300s Firmware	All versions	—
Netapp	H500s Firmware	All versions	—
Netapp	H700s Firmware	All versions	—
Netapp	H300e Firmware	All versions	—
Netapp	H500e Firmware	All versions	—
Netapp	H700e Firmware	All versions	—
Netapp	H410s Firmware	All versions	—
Netapp	H410c Firmware	All versions	—
Netapp	Cloud Backup	All versions	—
Siemens	Sinec Infrastructure Network Services	< 1.0.1.1	—
Oracle	Http Server	12.2.1.3.0	—
Oracle	Http Server	12.2.1.4.0	—
Oracle	Zfs Storage Appliance Kit	8.8	—

References

https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch, Third Party Advisory
https://kb.isc.org/v1/docs/cve-2021-25219Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00001.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EF4NAVRV4H3W4GA3LGGZYUKD3HSJBAVW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YGV7SA27CTYLGFJSPUM3V36ZWK7WWDI4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTKC4E3HUOLYN5IA4EBL4VAQSWG2ZVTX/
https://security.gentoo.org/glsa/202210-25Third Party Advisory
https://security.netapp.com/advisory/ntap-20211118-0002/Third Party Advisory
https://www.debian.org/security/2021/dsa-4994Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.htmlThird Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch, Third Party Advisory
https://kb.isc.org/v1/docs/cve-2021-25219Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00001.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EF4NAVRV4H3W4GA3LGGZYUKD3HSJBAVW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YGV7SA27CTYLGFJSPUM3V36ZWK7WWDI4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTKC4E3HUOLYN5IA4EBL4VAQSWG2ZVTX/
https://security.gentoo.org/glsa/202210-25Third Party Advisory
https://security.netapp.com/advisory/ntap-20211118-0002/Third Party Advisory
https://www.debian.org/security/2021/dsa-4994Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.htmlThird Party Advisory

Timeline

Published: Oct 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-25219?

How severe is CVE-2021-25219?

CVE-2021-25219 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 8.00% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25219?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-25219?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST