CVE-2022-33989Network attack vector

DNS cache poisoning via static UDP source port

Published Aug 15, 2022 · Updated Aug 3, 2024

DNS cache poisoning in dproxy-nexgen allows remote attackers to redirect client connections through spoofed upstream DNS replies. The DNS forwarder selects one UDP source port at boot and then reuses it for every query to upstream resolvers, removing per-query source-port entropy. Exploitation requires inducing DNS queries from a client and racing forged replies that impersonate the upstream resolver; a successful race inserts attacker-chosen records into the shared cache.

CVSS severity5.3
Medium
EPSS probability1.00%
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 dproxy-nexgen allows remote attackers to redirect client connections through spoofed upstream DNS replies. The DNS forwarder selects one UDP source port at boot and then reuses it for every query to upstream resolvers, removing per-query source-port entropy. Exploitation requires inducing DNS queries from a client and racing forged replies that impersonate the upstream resolver; a successful race inserts attacker-chosen records into the shared cache.

The record

CVE
CVE-2022-33989
Published
Aug 15, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-331, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-331Insufficient Entropy
T1557Adversary-in-the-Middle

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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