CVE-2021-25215
An assertion check can fail while answering queries for DNAME records that require the DNAME to be processed to resolve itself
02 Description
An assertion check can fail while answering queries for DNAME records that require the DNAME to be processed to resolve itself
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 11.69% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 96.0% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-04-29 00:55Z5 YR AGO
- Last updated
- 2024-09-16 22:02Z2 YR AGO
- Reserved
- 2021-01-15
- Assigning CNA
- isc
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.5)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-617Reachable AssertionBase
- Data version
- 5.1
- Document digest
- 7413138044b5c389f112486befd58038a5594595ebe450545a7f678ed400647e
05 Affected products
06 References
- kb.isc.orghttps://kb.isc.org/v1/docs/cve-2021-25215
- www.openwall.com[oss-security] 20210428 ISC discloses three BIND vulnerabilities (CVE-2021-25214, CVE-2021-25215, and CVE-2021-25216)http://www.openwall.com/lists/oss-security/2021/04/29/1
- www.openwall.com[oss-security] 20210429 Re: ISC discloses three BIND vulnerabilities (CVE-2021-25214, CVE-2021-25215, and CVE-2021-25216)http://www.openwall.com/lists/oss-security/2021/04/29/2
- www.openwall.com[oss-security] 20210429 Re: ISC discloses three BIND vulnerabilities (CVE-2021-25214, CVE-2021-25215, and CVE-2021-25216)http://www.openwall.com/lists/oss-security/2021/04/29/3
- www.openwall.com[oss-security] 20210429 Re: ISC discloses three BIND vulnerabilities (CVE-2021-25214, CVE-2021-25215, and CVE-2021-25216)http://www.openwall.com/lists/oss-security/2021/04/29/4
- www.debian.orgDSA-4909https://www.debian.org/security/2021/dsa-4909
- lists.debian.org[debian-lts-announce] 20210504 [SECURITY] [DLA 2647-1] bind9 security updatehttps://lists.debian.org/debian-lts-announce/2021/05/msg00001.html
- lists.fedoraproject.orgFEDORA-2021-ace61cbee1https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VEC2XG4Q2ODTN2C4CGXEIXU3EUTBMK7L/
- lists.fedoraproject.orgFEDORA-2021-47f23870echttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDSRPCJQ7MZC6CENH5PO3VQOFI7VSWBE/
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20210521-0006/
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
07 Remediation
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
08 Fixed in
Arch Linux
- bind Fixed in 9.16.15-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
Debian 12
- bind9 Fixed in 1:9.16.15-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- bind9 Fixed in 1:9.16.15-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- bind9 Fixed in 1:9.16.15-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- bind9 Fixed in 1:9.10.3.dfsg.P4-8ubuntu1.19
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- bind9 Fixed in 1:9.11.3+dfsg-1ubuntu1.15
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- bind9 Fixed in 1:9.16.1-0ubuntu2.8
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- bind9 Fixed in 1:9.9.5.dfsg-3ubuntu0.19+esm13Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.