CVE-2022-30699Network attack vector

Persistent rogue-domain resolution via expired delegation overwrite

Published Aug 1, 2022 · Updated Sep 16, 2024

DNS cache poisoning in NLnet Labs Unbound 1.16.1 and earlier allows remote attackers to keep revoked malicious domains resolvable. The resolver accepts a delayed delegation response after its cached delegation expires and overwrites the entry without considering query start time. The attacker must control the queried domain's nameserver and time responses near delegation expiry, enabling repeated bypass of a parent-zone takedown.

CVSS severity6.5
Medium
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DNS cache poisoning in NLnet Labs Unbound 1.16.1 and earlier allows remote attackers to keep revoked malicious domains resolvable. The resolver accepts a delayed delegation response after its cached delegation expires and overwrites the entry without considering query start time. The attacker must control the queried domain's nameserver and time responses near delegation expiry, enabling repeated bypass of a parent-zone takedown.

The record

CVE
CVE-2022-30699
Published
Aug 1, 2022
Updated
Sep 16, 2024
Vendor
NLnet Labs
Product
Unbound
Classifications
CWE-613
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=1.16.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

NLnet Labs · Unboundversion=unspecified <=1.16.1

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-613Insufficient Session Expiration

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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