CVE-2016-5180

CVE-2016-5180 is a critical-severity vulnerability in C-ares with a CVSS 3.x base score of 9.8. 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: Critical (CVSS 3.x base score 9.8)
• CVSS v2: 7.5
• EPSS exploit prediction: 9% (94th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-787
• Affected product: C-ares
• Published: 2016-10-03
• Last modified: 2026-06-17

Description

Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly execute arbitrary code via a hostname with an escaped trailing dot.

Frequently asked questions

What is CVE-2016-5180?

Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly execute arbitrary code via a hostname with an escaped trailing dot.

How severe is CVE-2016-5180?

CVE-2016-5180 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-5180 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-5180?

CVE-2016-5180 primarily affects C-ares. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-5180?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2016-5180 published?

CVE-2016-5180 was published on 2016-10-03 and last updated on 2026-06-17.

References

• http://rhn.redhat.com/errata/RHSA-2017-0002.html
• http://www.debian.org/security/2016/dsa-3682
• http://www.securityfocus.com/bid/93243
• http://www.ubuntu.com/usn/USN-3143-1
• https://c-ares.haxx.se/CVE-2016-5180.patch
• https://c-ares.haxx.se/adv_20160929.html
• https://googlechromereleases.blogspot.in/2016/09/stable-channel-updates-for-chrome-os.html
• https://security.gentoo.org/glsa/201701-28
• https://source.android.com/security/bulletin/2017-01-01.html

Affected products (30)

• cpe:2.3:a:c-ares:c-ares:1.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.3.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.3.1:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.3.2:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.4.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.5.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.5.2:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.5.3:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.6.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.1:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.2:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.3:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.4:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.7.5:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.8.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.9.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.9.1:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares:c-ares:1.10.0:*:*:*:*:*:*:*
• cpe:2.3:a:c-ares_project:c-ares:1.11.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:a:nodejs:node.js:*:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.10:*:*:*:*:*:*:*

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