CVE-2024-25629 | c-ares out of bounds read in ares__read_line()

c-ares is a C library for asynchronous DNS requests. `ares__read_line()` is used to parse local configuration files such as `/etc/resolv.conf`, `/etc/nsswitch.conf`, the `HOSTALIASES` file, and if using a c-ares version prior to 1.27.0, the `/etc/hosts` file. If any of these configuration files has an embedded `NULL` character as the first character in a new line, it can lead to attempting to read memory prior to the start of the given buffer which may result in a crash. This issue is fixed in c-ares 1.27.0. No known workarounds exist.

Published: 2024-02-23 Last update: 2025-02-05 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-25629 is rated Low Risk (23.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-25629

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-13 0.05% 0.06% +0.01%
2 2025-03-30 0.06% 0.05% -0.02%
3 2025-03-29 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-25629

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2024-25629

OS Trackers for CVE-2024-25629

vendor priority summary link
alpine — CVE-2024-25629: 1 source package rows (c-ares); 12 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 5. https://security.alpinelinux.org/vuln/CVE-2024-25629
debian not yet assigned CVE-2024-25629 not yet assigned priority: Debian including 1 source packages (c-ares), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2024-25629
redhat low — https://access.redhat.com/security/cve/CVE-2024-25629
suse medium CVE-2024-25629 severity moderate: SUSE including 279 source package names (0.3.2-1.2:libcares2-1.19.1-150000.3.26.1, 0.3.32-3.4:libcares2-1.19.1-150000.3.26.1, …), 534 product×package rows across 270 product lines (Container bci/nodejs, Container containers/apache-pulsar, … (270 product lines)): Fixed 334, Known Affected 200. https://www.suse.com/security/cve/CVE-2024-25629/
ubuntu medium CVE-2024-25629 medium priority: Ubuntu including 1 source packages (c-ares), 7 status rows across 7 suites (bionic, focal, jammy, mantic, trusty, upstream, xenial): released 6, ignored 1. https://ubuntu.com/security/CVE-2024-25629

Affected software / configurations for CVE-2024-25629

Vendor Product Version Raw CPE
c-ares c-ares < 1.27.0 cpe:2.3:a:c-ares:c-ares:*:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
fedoraproject fedora 40 cpe:2.3:o:fedoraproject:fedora:40:*:*:*:*:*:*:*

References for CVE-2024-25629

cvelogic Threat Intelligence