CVE-2023-43754 Permalink previews displayed for posts in archived channels even if users are disallowed to view archived channels

What is CVE-2023-43754?

CVE-2023-43754 is a medium-severity vulnerability in Mattermost Mattermost, published on 27 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled.

Weakness: CWE-200

Which versions are affected by CVE-2023-43754?

8 open source packages ship an affected version, including github.com/mattermost/mattermost/server/v8 and github.com/mattermost/mattermost-server/v6. It affects 1 product.

Products include Mattermost Mattermost.

How do I fix CVE-2023-43754?

Upgrade github.com/mattermost/mattermost/server/v8 to a fixed version for your release line: 8.1.4, 9.0.2 or 9.1.1.

Is CVE-2023-43754 being exploited?

There is no known exploitation of CVE-2023-43754 in the wild and no public exploit code.

Other vulnerabilities in Mattermost Mattermost

• CVE-2019-20851 Path traversal in n/a Critical 9.1
• CVE-2024-39274 Malicious remote can add users to arbitrary teams and channels High 8.7
• CVE-2024-39777 Malicious remote can invite itself to an arbitrary local channel High 8.7
• CVE-2024-39830 Timing attack during remote cluster token comparison when shared channels are enabled High 8.1
• CVE-2023-3615 Lack of server certificate validation in websockets connection High 8.1

All Mattermost Mattermost vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-jjr7-372r-cx7x.