How severe is CVE-2023-31130?

CVE-2023-31130 has a CVSS 3.x base score of 4.1, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-31130 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-31130?

CVE-2023-31130 primarily affects C-ares Project C-ares. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-31130?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-31130 published?

CVE-2023-31130 was published on 2023-05-25 and last updated on 2026-06-17.

CVE-2023-31130

CVE-2023-31130 is a medium-severity vulnerability in C-ares Project C-ares with a CVSS 3.x base score of 4.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 4.1)
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: C-ares Project C-ares
Published: 2023-05-25
Last modified: 2026-06-17

Description

c-ares is an asynchronous resolver library. ares_inet_net_pton() is vulnerable to a buffer underflow for certain ipv6 addresses, in particular "0::00:00:00/2" was found to cause an issue. C-ares only uses this function internally for configuration purposes which would require an administrator to configure such an address via ares_set_sortlist(). However, users may externally use ares_inet_net_pton() for other purposes and thus be vulnerable to more severe issues. This issue has been fixed in 1.19.1.

Frequently asked questions

What is CVE-2023-31130?: c-ares is an asynchronous resolver library. ares_inet_net_pton() is vulnerable to a buffer underflow for certain ipv6 addresses, in particular "0::00:00:00/2" was found to cause an issue. C-ares only uses this function internally for configuration purposes which would require an administrator to configure such an address via ares_set_sortlist(). However, users may externally use ares_inet_net_pton() for other purposes and thus be vulnerable to more severe issues. This issue has been fixed in 1.19.1.
How severe is CVE-2023-31130?: CVE-2023-31130 has a CVSS 3.x base score of 4.1, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-31130 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-31130?: CVE-2023-31130 primarily affects C-ares Project C-ares. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-31130?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-31130 published?: CVE-2023-31130 was published on 2023-05-25 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:c-ares_project:c-ares:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

More vulnerabilities in C-ares Project C-ares

CVE-2016-5180 — Critical (CVSS 9.8): Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to…
CVE-2022-4904 — High (CVSS 8.6): A flaw was found in the c-ares package. The ares_set_sortlist is missing checks about the validity of the input string,…
CVE-2023-32067 — High (CVSS 7.5): c-ares is an asynchronous resolver library. c-ares is vulnerable to denial of service. If a target resolver sends a…
CVE-2020-8277 — High (CVSS 7.5): A Node.js application that allows an attacker to trigger a DNS request for a host of their choice could trigger a…
CVE-2017-1000381 — High (CVSS 7.5): The c-ares function `ares_parse_naptr_reply()`, which is used for parsing NAPTR responses, could be triggered to read…
CVE-2023-31147 — Medium (CVSS 5.9): c-ares is an asynchronous resolver library. When /dev/urandom or RtlGenRandom() are unavailable, c-ares uses rand() to…

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