CVE Vulnerabilities

CVE-2013-4169

Improper Link Resolution Before File Access ('Link Following')

Published: Sep 10, 2013 | Modified: Sep 12, 2013
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
6.9 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
6.2 IMPORTANT
AV:L/AC:H/Au:N/C:C/I:C/A:C
RedHat/V3
Ubuntu
MEDIUM

GNOME Display Manager (gdm) before 2.21.1 allows local users to change permissions of arbitrary directories via a symlink attack on /tmp/.X11-unix/.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Gnome_display_manager Gnome * 2.21 (including)
Gnome_display_manager Gnome 0.7 (including) 0.7 (including)
Gnome_display_manager Gnome 1.0 (including) 1.0 (including)
Gnome_display_manager Gnome 2.0 (including) 2.0 (including)
Gnome_display_manager Gnome 2.2 (including) 2.2 (including)
Gnome_display_manager Gnome 2.13 (including) 2.13 (including)
Gnome_display_manager Gnome 2.14 (including) 2.14 (including)
Gnome_display_manager Gnome 2.14.1 (including) 2.14.1 (including)
Gnome_display_manager Gnome 2.14.2 (including) 2.14.2 (including)
Gnome_display_manager Gnome 2.14.3 (including) 2.14.3 (including)
Gnome_display_manager Gnome 2.14.4 (including) 2.14.4 (including)
Gnome_display_manager Gnome 2.14.5 (including) 2.14.5 (including)
Gnome_display_manager Gnome 2.14.6 (including) 2.14.6 (including)
Gnome_display_manager Gnome 2.14.7 (including) 2.14.7 (including)
Gnome_display_manager Gnome 2.14.8 (including) 2.14.8 (including)
Gnome_display_manager Gnome 2.14.9 (including) 2.14.9 (including)
Gnome_display_manager Gnome 2.14.10 (including) 2.14.10 (including)
Gnome_display_manager Gnome 2.14.11 (including) 2.14.11 (including)
Gnome_display_manager Gnome 2.14.12 (including) 2.14.12 (including)
Gnome_display_manager Gnome 2.15 (including) 2.15 (including)
Gnome_display_manager Gnome 2.16 (including) 2.16 (including)
Gnome_display_manager Gnome 2.16.1 (including) 2.16.1 (including)
Gnome_display_manager Gnome 2.16.2 (including) 2.16.2 (including)
Gnome_display_manager Gnome 2.17 (including) 2.17 (including)
Gnome_display_manager Gnome 2.18 (including) 2.18 (including)
Gnome_display_manager Gnome 2.18.1 (including) 2.18.1 (including)
Gnome_display_manager Gnome 2.18.2 (including) 2.18.2 (including)
Gnome_display_manager Gnome 2.18.3 (including) 2.18.3 (including)
Gnome_display_manager Gnome 2.19 (including) 2.19 (including)
Gnome_display_manager Gnome 2.19.1 (including) 2.19.1 (including)
Gnome_display_manager Gnome 2.19.2 (including) 2.19.2 (including)
Gnome_display_manager Gnome 2.19.3 (including) 2.19.3 (including)
Gnome_display_manager Gnome 2.19.4 (including) 2.19.4 (including)
Gnome_display_manager Gnome 2.20.0 (including) 2.20.0 (including)
Gnome_display_manager Gnome 2.20.1 (including) 2.20.1 (including)
Gnome_display_manager Gnome 2.20.2 (including) 2.20.2 (including)
Gnome_display_manager Gnome 2.20.3 (including) 2.20.3 (including)
Gnome_display_manager Gnome 2.20.4 (including) 2.20.4 (including)
Gnome_display_manager Gnome 2.20.5 (including) 2.20.5 (including)
Gnome_display_manager Gnome 2.20.6 (including) 2.20.6 (including)
Gnome_display_manager Gnome 2.20.7 (including) 2.20.7 (including)
Gnome_display_manager Gnome 2.20.8 (including) 2.20.8 (including)
Gnome_display_manager Gnome 2.20.9 (including) 2.20.9 (including)
Gnome_display_manager Gnome 2.20.10 (including) 2.20.10 (including)
Red Hat Enterprise Linux 5 RedHat gdm-1:2.16.0-59.el5_9.1 *
Red Hat Enterprise Linux 5 RedHat initscripts-0:8.45.42-2.el5_9.1 *
Gdm Ubuntu lucid *

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References