Vulnerabilities > CVE-2018-8885 - Race Condition vulnerability in Canonical Screen-Resolution-Extra and Ubuntu Linux

047910
CVSS 4.4 - MEDIUM
Attack vector
LOCAL
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
local
canonical
CWE-362
nessus

Summary

screenresolution-mechanism in screen-resolution-extra 0.17.2 does not properly use the PolicyKit D-Bus API, which allows local users to bypass intended access restrictions by leveraging a race condition via a setuid or pkexec process that is mishandled in a PolicyKitService._check_permission call.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
    This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-3607-1.NASL
descriptionIt was discovered that Screen Resolution Extra was using PolicyKit in an unsafe manner. A local attacker could potentially exploit this issue to bypass intended PolicyKit authorizations. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
last seen2020-06-01
modified2020-06-02
plugin id108658
published2018-03-27
reporterUbuntu Security Notice (C) 2018-2019 Canonical, Inc. / NASL script (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/108658
titleUbuntu 14.04 LTS / 16.04 LTS / 17.10 : screen-resolution-extra vulnerability (USN-3607-1)