Improper Access Control

github.com/mattermost/mattermost-server is vulnerable to Improper Access Control. The vulnerability is due to improper validation of remote server requests in shared channels with multiple connected remote servers, allowing a malicious remote server to change the profile images of users belonging...

CVE-2024-36257

Mattermost versions 9.5.x = 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious...

CVE-2024-39830 Timing attack during remote cluster token comparison when shared channels are enabled

Mattermost versions 9.8.x = 9.8.0, 9.7.x = 9.7.4, 9.6.x = 9.6.2 and 9.5.x = 9.5.5, when shared channels are enabled, fail to use constant time comparison for remote cluster tokens which allows an attacker to retrieve the remote cluster token via a timing attack during remote cluster token...

CVE-2024-39830

Mattermost CVE-2024-39830 affects Mattermost server versions 9.8.x through 9.5.x (specific fixes: 9.8.0, 9.7.4, 9.6.2, 9.5.5 and earlier). The root cause is non-constant time comparison for remote cluster tokens during remote cluster token checks when shared channels are enabled, which can allow ...

CVE-2024-39830 Timing attack during remote cluster token comparison when shared channels are enabled

Mattermost versions 9.8.x = 9.8.0, 9.7.x = 9.7.4, 9.6.x = 9.6.2 and 9.5.x = 9.5.5, when shared channels are enabled, fail to use constant time comparison for remote cluster tokens which allows an attacker to retrieve the remote cluster token via a timing attack during remote cluster token...

CVE-2024-36257 Lack of permission check when updating the profile picture of a remote user (shared channels enabled)

Mattermost versions 9.5.x = 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious...

CVE-2024-36257 Lack of permission check when updating the profile picture of a remote user (shared channels enabled)

Mattermost versions 9.5.x = 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious...

CVE-2024-36257 Lack of permission check when updating the profile picture of a remote user (shared channels enabled)

Mattermost versions 9.5.x = 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious...

PT-2024-26936 · Mattermost · Mattermost

Name of the Vulnerable Software and Affected Versions: Mattermost versions 9.5.x through 9.5.5 Mattermost version 9.8.0 Description: The issue arises when Mattermost is used with shared channels and multiple remote servers are connected. In such cases, the system fails to verify that the remote...

Slack: Shared-channel BETA persists integration after unshare

@oneiroi discovered a bug in the Shared Channels Beta wherein notifications may still be delivered to an unshared channel previously shared. This did not affect data not in notifications, and we patched and performed a thorough investigation. Thanks for the report @oneiroi!...