CVE-2017-18594
CVE-2017-18594 is a high-severity vulnerability in Nmap with a CVSS 3.x base score of 7.5. 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-415.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 3% (86th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-415
- Affected product: Nmap
- Published:
- Last modified:
Description
nse_libssh2.cc in Nmap 7.70 is subject to a denial of service condition due to a double free when an SSH connection fails, as demonstrated by a leading \n character to ssh-brute.nse or ssh-auth-methods.nse.
Frequently asked questions
- What is CVE-2017-18594?
- nse_libssh2.cc in Nmap 7.70 is subject to a denial of service condition due to a double free when an SSH connection fails, as demonstrated by a leading \n character to ssh-brute.nse or ssh-auth-methods.nse.
- How severe is CVE-2017-18594?
- CVE-2017-18594 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2017-18594 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2017-18594?
- CVE-2017-18594 affects Nmap. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2017-18594?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2017-18594 published?
- CVE-2017-18594 was published on 2019-08-29 and last updated on 2026-06-17.
References
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00073.html
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00075.html
- https://github.com/AMatchandaHaystack/Research/blob/master/Nmap%26libsshDF
- https://github.com/nmap/nmap/commit/350bbe0597d37ad67abe5fef8fba984707b4e9ad
- https://github.com/nmap/nmap/issues/1077
- https://github.com/nmap/nmap/issues/1227
- https://seclists.org/nmap-announce/2019/0
- https://seclists.org/nmap-dev/2018/q2/45
Affected products (1)
- cpe:2.3:a:nmap:nmap:7.70:*:*:*:*:*:*:*
More vulnerabilities in Nmap
- CVE-2018-15173 — High (CVSS 7.5): Nmap through 7.70, when the -sV option is used, allows remote attackers to cause a denial of service (stack consumption…
- CVE-2013-4885 — Medium (CVSS 6.8): The http-domino-enum-passwords.nse script in NMap before 6.40, when domino-enum-passwords.idpath is set, allows remote…
- CVE-2026-58058 — Medium (CVSS 6.5): Nmap through 7.99 does not keep the IPv6 extension-header walk within the captured packet in ipv6_get_data_primitive…
- CVE-2018-1000161 — Medium (CVSS 5.7): nmap version 6.49BETA6 through 7.60, up to and including SVN revision 37147 contains a Directory Traversal…
Other CWE-415 (Double Free) vulnerabilities
- CVE-2018-0101 — Critical (CVSS 10.0): A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA)…
- CVE-2026-8925 — Critical (CVSS 9.8): The curl logic that works with SASL authentication could end up cleaning up the GSASL context *twice* without clearing…
- CVE-2020-37239 — Critical (CVSS 9.8): libbabl 0.1.62 contains a broken double free detection vulnerability that allows attackers to bypass memory safety…
- CVE-2026-43414 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Completely fix fcport double…
- CVE-2026-43011 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When…
- CVE-2026-31609 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid double-free in…