FreeBSD : libXdmcp -- insufficient entropy generating session keys (1b6a10e9-4b7b-11e9-9e89-54e1ad3d6335)

medium Nessus Plugin ID 122987



The remote FreeBSD host is missing a security-related update.


The freedesktop and project reports :

It was discovered that libXdmcp before 1.1.3 used weak entropy to generate session keys on platforms without arc4random_buf() but with getentropy(). On a multi-user system using xdmcp, a local attacker could potentially use information available from the process list to brute force the key, allowing them to hijack other users' sessions.

Please note, that since FreeBSD provides arc4random_buf(), it is unknown if FreeBSD is affected by this vulnerability


Update the affected package.

See Also

Plugin Details

Severity: Medium

ID: 122987

File Name: freebsd_pkg_1b6a10e94b7b11e99e8954e1ad3d6335.nasl

Version: 1.4

Type: local

Published: 3/21/2019

Updated: 2/3/2020

Risk Information


Risk Factor: Medium

Score: 4.4


Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N

Temporal Vector: E:POC/RL:OF/RC:C


Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:libXdmcp, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/21/2019

Vulnerability Publication Date: 4/4/2017

Reference Information

CVE: CVE-2017-2625