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Fencer Vulns
medium 6.5

CVE-2017-2625 json

It was discovered that libXdmcp before 1.1.2 including used weak entropy to generate session keys.

published 2018-07-27 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-11786

cvss
6.5
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

It was discovered that libXdmcp before 1.1.2 including used weak entropy to generate session keys. 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.

Patch / fix

  • x.org libxdmcp 1.1.2
  • libxdmcp Debian 14, Debian 13, Debian 12 1:1.1.2-2

debian advisories DEBIAN-CVE-2017-2625

  • libxdmcp Ubuntu 18.04 LTS 1:1.1.2-3
  • libxdmcp Ubuntu Pro 14.04 LTS 1:1.1.1-1ubuntu0.1~esm1
  • libxdmcp Ubuntu Pro 16.04 LTS 1:1.1.2-1.1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2017-2625

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • mesa RHEL 7 17.0.1-6.20170307.el7
  • libXi RHEL 7 1.7.9-1.el7
  • libXt RHEL 7 1.1.5-3.el7
  • libXv RHEL 7 1.0.11-1.el7
  • libdrm RHEL 7 2.4.74-1.el7
  • libICE RHEL 7 1.0.9-9.el7
  • libX11 RHEL 7 1.6.5-1.el7
  • libXaw RHEL 7 1.0.13-4.el7

red hat advisories RHSA-2017:1865

  • libXdmcp SLES for SAP 12 SP3, SLES 12 SP3, SLED 12 SP3 +1 more 1.1.1-12.1
  • xorg-x11-libXdmcp SLES for SAP 11 SP4, SLES 11 SP4, SLE Software Development Kit 11 SP4 7.4-3.1
  • libXdmcp SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +2 more 1.1.1-10.1

suse advisories SUSE-SU-2018:0338-1SUSE-SU-2017:1868-1SUSE-SU-2017:1862-1

  • libXdmcp openSUSE Tumbleweed 1.1.3-1.11

opensuse advisories openSUSE-SU-2024:10920-1

  • libxdmcp Alpine 3.24, Alpine 3.23, Alpine 3.22 +16 more 1.1.2-r3

alpine advisories ALPINE-CVE-2017-2625

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-2625 updated cvss 6.5

libXdmcp: weak entropy usage for session keys

  • Red Hat Enterprise Linux 5 libXdmcp Red Hat Enterprise Linux 6 libXdmcp
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) libxcb 1.12-1.el7, libXi 1.7.9-1.el7, libXt 1.1.5-3.el7, libICE 1.0.9-9.el7, libX11 1.6.5-1.el7, libXv 1.0.11-1.el7, +35 more Red Hat Enterprise Linux Client Optional (v. 7) xcb-proto 1.12-2.el7, vulkan 1.0.39.1-2.el7, drm-utils 2.4.74-1.el7, libevdev-utils 1.5.6-1.el7, vulkan-filesystem 1.0.39.1-2.el7, mesa-libOSMesa 17.0.1-6.20170307.el7, +1 more Red Hat Enterprise Linux ComputeNode (v. 7) libxcb 1.12-1.el7, libXi 1.7.9-1.el7, libXt 1.1.5-3.el7, libICE 1.0.9-9.el7, libX11 1.6.5-1.el7, libXv 1.0.11-1.el7, +26 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) libwacom 0.24-1.el7, xcb-proto 1.12-2.el7, vulkan 1.0.39.1-2.el7, drm-utils 2.4.74-1.el7, libwacom-data 0.24-1.el7, libxkbcommon 0.7.1-1.el7, +6 more Red Hat Enterprise Linux Server (v. 7) libxcb 1.12-1.el7, libXi 1.7.9-1.el7, libXt 1.1.5-3.el7, libICE 1.0.9-9.el7, libX11 1.6.5-1.el7, libXv 1.0.11-1.el7, +35 more Red Hat Enterprise Linux Server Optional (v. 7) libwacom 0.24-1.el7, xcb-proto 1.12-2.el7, vulkan 1.0.39.1-2.el7, drm-utils 2.4.74-1.el7, libwacom-data 0.24-1.el7, libevdev-utils 1.5.6-1.el7, +3 more
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 7) libxcb 1.12-1.el7, libXi 1.7.9-1.el7, libXt 1.1.5-3.el7, libICE 1.0.9-9.el7, libX11 1.6.5-1.el7, libXv 1.0.11-1.el7, +35 more Red Hat Enterprise Linux Workstation Optional (v. 7) xcb-proto 1.12-2.el7, vulkan 1.0.39.1-2.el7, drm-utils 2.4.74-1.el7, libevdev-utils 1.5.6-1.el7, vulkan-filesystem 1.0.39.1-2.el7, mesa-libOSMesa 17.0.1-6.20170307.el7, +1 more
    fixed: vendor fix RHSA-2017:1865

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • x41-dsec.de https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 6.5 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD 3.0 5.5 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • Xorg libXdmcp

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.