CVE-2023-33285Network attack vector

Application crash via malformed DNS reply

Published May 22, 2023 · Updated Jan 21, 2025

Buffer over-read in Qt QDnsLookup allows remote attackers to crash affected Unix applications via a crafted DNS reply. The Unix parser trusts a DNS record's 16-bit RDATA length without verifying that its header and data remain within the received buffer. The application must explicitly use QDnsLookup, and the attacker must receive its query and answer from the queried server address; normal name resolution is unaffected.

CVSS severity5.3
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer over-read in Qt QDnsLookup allows remote attackers to crash affected Unix applications via a crafted DNS reply. The Unix parser trusts a DNS record's 16-bit RDATA length without verifying that its header and data remain within the received buffer. The application must explicitly use QDnsLookup, and the attacker must receive its query and answer from the queried server address; normal name resolution is unaffected.

The record

CVE
CVE-2023-33285
Published
May 22, 2023
Updated
Jan 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 2025Record 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:N/A:L
5.3MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

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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