apportproject apport CVE-2020-8831 in Apportproject and Canonical Products
Published on April 22, 2020

World writable root owned lock file created in user controllable location

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Apport creates a world writable lock file with root ownership in the world writable /var/lock/apport directory. If the apport/ directory does not exist (this is not uncommon as /var/lock is a tmpfs), it will create the directory, otherwise it will simply continue execution using the existing directory. This allows for a symlink attack if an attacker were to create a symlink at /var/lock/apport, changing apport's lock file location. This file could then be used to escalate privileges, for example. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2020-8831 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Type

Creation of Temporary File in Directory with Insecure Permissions

The software creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file. On some operating systems, the fact that the temporary file exists may be apparent to any user with sufficient privileges to access that directory. Since the file is visible, the application that is using the temporary file could be known. If one has access to list the processes on the system, the attacker has gained information about what the user is doing at that time. By correlating this with the applications the user is running, an attacker could potentially discover what a user's actions are. From this, higher levels of security could be breached.


Products Associated with CVE-2020-8831

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2020-8831 are published in these products:

Apportproject Apport
 
Canonical Ubuntu Linux
 
Canonical Apport
 

Affected Versions

Canonical Apport:

Exploit Probability

EPSS
0.12%
Percentile
30.43%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.