HOMEVULNERABILITIESCVE-2021-25219
MEDIUM

CVE-2021-25219

NVD-CWE-noinfoPublished: October 27, 2021· Updated: Jun 17, 2026

5.3
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-25219 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
isc1 product(s)
bind
netapp17 product(s)
h300s firmwareh300sh500s firmwareh500sh700s firmwareh700sh300e firmwareh300eh500e firmwareh500eh700e firmwareh700e+5
Oracle2 product(s)
http serverzfs storage appliance kit
siemens1 product(s)
sinec infrastructure network services
Source: NVD CPE · 47 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
ADVISORYhttps://kb.isc.org/v1/docs/cve-2021-25219
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/11/msg00001.html
ADVISORYhttps://security.gentoo.org/glsa/202210-25
ADVISORYhttps://security.netapp.com/advisory/ntap-20211118-0002/
ADVISORYhttps://www.debian.org/security/2021/dsa-4994
ADVISORYhttps://www.oracle.com/security-alerts/cpuapr2022.html
ADVISORYhttps://kb.isc.org/v1/docs/cve-2021-25219
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/11/msg00001.html
ADVISORYhttps://security.gentoo.org/glsa/202210-25
ADVISORYhttps://security.netapp.com/advisory/ntap-20211118-0002/
ADVISORYhttps://www.debian.org/security/2021/dsa-4994
ADVISORYhttps://www.oracle.com/security-alerts/cpuapr2022.html

All References (20)

→
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/

Quick Facts

CVE IDCVE-2021-25219
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected6 vendor(s)
PublishedOct 27, 2021

Related CVEs (NVD-CWE-noinfo)

CVE-2015-6787
10.0
CVE-2009-3099
10.0
CVE-2017-6326
10.0
CVE-2010-0071
10.0
CVE-2006-3698
10.0
CVE-2009-1422
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-25219 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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