CVE-2023-2783 App Framework does not checks for the secret provided in the incoming webhook request

What is CVE-2023-2783?

CVE-2023-2783 is a medium-severity missing authorization vulnerability in Mattermost Mattermost, published on 16 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost Apps Framework fails to verify that a secret provided in the incoming webhook request allowing an attacker to modify the contents of the post sent by the Apps.

Weakness: CWE-862

Which versions are affected by CVE-2023-2783?

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

Products include Mattermost Mattermost.

How do I fix CVE-2023-2783?

Upgrade github.com/mattermost/mattermost-server/v6 to a fixed version for your release line: 6.0.0-20230511130429-1629a6ca7fed, 7.8.5, 7.10.1 or 7.9.4.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2023-2783 being exploited?

There is no known exploitation of CVE-2023-2783 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-455c-vqrf-mghr.