Mattermost <=9.9.x Remote Username Spoof in Shared Channels (CVE-2024-39839)
CVE-2024-39839 Published on August 1, 2024

Remote username set to an arbitrary string by remote user
Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow users to set their own remote username, when shared channels were enabled, which allows a user on a remote to set their remote username prop to an arbitrary string, which would be then synced to the local server as long as the user hadn't been synced before.

NVD

Vulnerability Analysis

CVE-2024-39839 can be exploited with network 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, with no impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
LOW
Availability Impact:
NONE

Weakness Type

What is an Authorization Vulnerability?

The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

CVE-2024-39839 has been classified to as an Authorization vulnerability or weakness.


Products Associated with CVE-2024-39839

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Mattermost Server
 
MatterMost
 

Affected Versions

Mattermost:

Exploit Probability

EPSS
0.22%
Percentile
44.03%

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.