CVE-2016-1888 Freebsd CVE debrief

Who should care

Administrators running FreeBSD systems that expose telnetd should treat this as a priority authentication-bypass issue. It matters most for environments where telnet service is still enabled, especially on the affected FreeBSD releases noted in the NVD record.

Technical summary

NVD assigns this issue CVSS 3.0 vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N and CWE-287. The vulnerability is described as a remote attack against telnetd where a sequence of memory allocation failures can cause arguments to be injected into login, resulting in authentication bypass. The affected versions listed are FreeBSD 9.3, 10.1, 10.2, 10.3, and 11.0.

Defensive priority

High. This is a remotely reachable authentication bypass with no privileges or user interaction required, and the impact is integrity compromise through unauthorized access. If telnetd is enabled on an affected host, remediation should be treated as urgent.

Recommended defensive actions

• Check whether telnetd is enabled or exposed on any FreeBSD systems in scope.
• Review FreeBSD systems matching the affected versions listed by NVD: 9.3, 10.1, 10.2, 10.3, and 11.0.
• Apply the vendor guidance from the FreeBSD security advisory for CVE-2016-1888.
• If telnet service is not strictly required, disable it and restrict network access to the service.
• Validate that patched or updated systems no longer expose the vulnerable telnetd behavior.

Evidence notes

All claims here are taken from the supplied NVD record and the linked FreeBSD advisory. The published date used is 2017-02-15T15:59:00.403Z from the supplied CVE timeline. No exploit steps or unsupported technical details are included.

Official resources