What’s Vulnerable › Vulnerabilities
CVE-2021-25214: A broken inbound incremental zone update (IXFR) can cause named to terminate unexpectedly
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 6.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-04-29 · updated 2026-06-17
- Weakness: CWE-617
Description
In BIND 9.8.5 -> 9.8.8, 9.9.3 -> 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 9 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 malformed IXFR triggering the flaw described above, the named process will terminate due to a failed assertion the next time the transferred secondary zone is refreshed.
Affected products
- Debian Linux: 9.0, 10.0
- Fedoraproject Fedora: 33, 34
- ISC BIND: from 9.8.5 through 9.8.8; from 9.9.3 before 9.11.31; from 9.12.0 before 9.16.15; from 9.17.0 before 9.17.12; 9.9.3-s1, 9.9.12-s1, 9.9.13-s1, 9.10.5-s1, 9.10.7-s1, 9.11.3-s1 (+13) — fixed in 9.11.31, 9.16.15, 9.17.12
- Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
- NetApp Aff 500F Firmware: all versions
- NetApp Aff A250 Firmware: all versions
- NetApp Cloud Backup: all versions
- NetApp H300E Firmware: all versions
- NetApp H300S Firmware: all versions
- NetApp H410S Firmware: all versions
- NetApp H500E Firmware: all versions
- NetApp H500S Firmware: all versions
- NetApp H700E Firmware: all versions
- NetApp H700S Firmware: all versions
- Siemens Sinec Infrastructure Network Services: before 1.0.1.1 — fixed in 1.0.1.1
How to fix
Upgrade to a fixed version: ISC BIND 9.11.31, 9.16.15, 9.17.12; Siemens Sinec Infrastructure Network Services 1.0.1.1. Check the vendor advisory for mitigations.
References
- http://www.openwall.com/lists/oss-security/2021/04/29/1
- http://www.openwall.com/lists/oss-security/2021/04/29/2
- http://www.openwall.com/lists/oss-security/2021/04/29/3
- http://www.openwall.com/lists/oss-security/2021/04/29/4
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
- https://kb.isc.org/v1/docs/cve-2021-25214
- https://lists.debian.org/debian-lts-announce/2021/05/msg00001.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VEC2XG4Q2ODTN2C4CGXEIXU3EUTBMK7L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDSRPCJQ7MZC6CENH5PO3VQOFI7VSWBE/
- https://security.netapp.com/advisory/ntap-20210521-0006/
- https://www.debian.org/security/2021/dsa-4909
- http://www.openwall.com/lists/oss-security/2021/04/29/1
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