CVE-2017-14493

CVE-2017-14493 is a critical-severity vulnerability in Thekelleys Dnsmasq with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 84% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

• Severity: Critical (CVSS 3.x base score 9.8)
• CVSS v2: 7.5
• EPSS exploit prediction: 84% (100th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-119
• Affected product: Thekelleys Dnsmasq
• Published: 2017-10-03
• Last modified: 2026-06-17

Description

Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DHCPv6 request.

Frequently asked questions

What is CVE-2017-14493?

Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DHCPv6 request.

How severe is CVE-2017-14493?

CVE-2017-14493 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-2017-14493 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 84% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-14493?

CVE-2017-14493 primarily affects Thekelleys Dnsmasq. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-14493?

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-2017-14493 published?

CVE-2017-14493 was published on 2017-10-03 and last updated on 2026-06-17.

References

• http://lists.opensuse.org/opensuse-security-announce/2017-10/msg00006.html
• http://nvidia.custhelp.com/app/answers/detail/a_id/4561
• http://thekelleys.org.uk/dnsmasq/CHANGELOG
• http://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=commit%3Bh=3d4ff1ba8419546490b464418223132529514033
• http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2017-005.txt
• http://www.debian.org/security/2017/dsa-3989
• http://www.securityfocus.com/bid/101085
• http://www.securitytracker.com/id/1039474
• http://www.ubuntu.com/usn/USN-3430-1
• http://www.ubuntu.com/usn/USN-3430-2
• https://access.redhat.com/errata/RHSA-2017:2836
• https://access.redhat.com/errata/RHSA-2017:2837
• https://access.redhat.com/security/vulnerabilities/3199382
• https://security.gentoo.org/glsa/201710-27
• https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html
• https://www.exploit-db.com/exploits/42943/
• https://www.kb.cert.org/vuls/id/973527
• https://www.mail-archive.com/dnsmasq-discuss%40lists.thekelleys.org.uk/msg11664.html
• https://www.mail-archive.com/dnsmasq-discuss%40lists.thekelleys.org.uk/msg11665.html
• https://www.synology.com/support/security/Synology_SA_17_59_Dnsmasq

Affected products (12)

• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:17.04:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:7.1:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
• cpe:2.3:o:opensuse:leap:42.2:*:*:*:*:*:*:*
• cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
• cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:*

More vulnerabilities in Thekelleys Dnsmasq

• CVE-2021-45957 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in answer_request (called from FuzzAnswerTheRequest and fuzz_rfc1035.c).…
• CVE-2021-45956 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in print_mac (called from log_packet and dhcp_reply). NOTE: the vendor's…
• CVE-2021-45955 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c)…
• CVE-2021-45954 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). NOTE: the…
• CVE-2021-45953 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from hash_questions and fuzz_util.c). NOTE: the…
• CVE-2021-45952 — Critical (CVSS 9.8): Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's…

All CVEs affecting Thekelleys Dnsmasq →

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• CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
• CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

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