HOMEVULNERABILITIESCVE-2021-25214
MEDIUM

CVE-2021-25214

CWE-617Published: April 29, 2021· Updated: Jun 17, 2026

6.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-25214 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
isc1 product(s)
bind
netapp20 product(s)
active iq unified managercloud backupaff a250 firmwareaff a250aff 500f firmwareaff 500fh300s firmwareh300sh500s firmwareh500sh700s firmwareh700s+8
siemens1 product(s)
sinec infrastructure network services
Source: NVD CPE · 43 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/1
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/2
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/3
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/4
ADVISORYhttps://kb.isc.org/v1/docs/cve-2021-25214
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/05/msg00001.html
ADVISORYhttps://security.netapp.com/advisory/ntap-20210521-0006/
ADVISORYhttps://www.debian.org/security/2021/dsa-4909
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/1
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/2
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/3
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/04/29/4
ADVISORYhttps://kb.isc.org/v1/docs/cve-2021-25214
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/05/msg00001.html
ADVISORYhttps://security.netapp.com/advisory/ntap-20210521-0006/
ADVISORYhttps://www.debian.org/security/2021/dsa-4909

All References (22)

→
http://www.openwall.com/lists/oss-security/2021/04/29/1Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/2Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/3Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/4Mailing List · Third Party Advisory
→
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch · Third Party Advisory
→
https://kb.isc.org/v1/docs/cve-2021-25214Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2021/05/msg00001.htmlMailing List · Third Party Advisory
→
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/Third Party Advisory
→
https://www.debian.org/security/2021/dsa-4909Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/1Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/2Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/3Mailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2021/04/29/4Mailing List · Third Party Advisory

Quick Facts

CVE IDCVE-2021-25214
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-617
CISA KEVNo
Affected5 vendor(s)
PublishedApr 29, 2021

Related CVEs (CWE-617)

CVE-2019-9795
9.8
CVE-2020-3615
9.8
CVE-2020-6617
8.8
CVE-2020-6619
8.8
CVE-2020-12417
8.8
CVE-2020-6623
8.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-25214 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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