CVE-2024-25629

Application crash via NUL-prefixed configuration line

Published Feb 23, 2024 · Updated Feb 13, 2025

Buffer under-read in c-ares before 1.27.0 allows local users to crash applications via a NUL-prefixed configuration-file line. In ares__read_line(), an initial NUL produces a zero length, but the parser still indexes the byte at length minus one, reading before the buffer. High privileges are required to modify the parsed local configuration, and the resulting availability impact is limited to the consuming application.

CVSS severity4.4
Medium
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer under-read in c-ares before 1.27.0 allows local users to crash applications via a NUL-prefixed configuration-file line. In ares__read_line(), an initial NUL produces a zero length, but the parser still indexes the byte at length minus one, reading before the buffer. High privileges are required to modify the parsed local configuration, and the resulting availability impact is limited to the consuming application.

The record

CVE
CVE-2024-25629
Published
Feb 23, 2024
Updated
Feb 13, 2025
Vendor
c-ares Project
Product
c-ares
Classifications
CWE-125, CWE-127, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 23, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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?

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

  1. Affected versionversion=< 1.27.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

c-ares Project · c-aresversion=< 1.27.0

Published CVSS scores

4.4GitHub CNACVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CWE-127Buffer Under-read
T1499.004Endpoint Denial of Service: Application 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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