CVE-2024-29977 Malicious remote can create arbitrary reactions on arbitrary posts

What is CVE-2024-29977?

CVE-2024-29977 is a low-severity missing authorization vulnerability in Mattermost Mattermost, published on 1 Aug 2024. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6 fail to properly validate synced reactions, when shared channels are enabled, which allows a malicious remote to create arbitrary reactions on arbitrary posts

Weakness: CWE-284

Which versions are affected by CVE-2024-29977?

8 open source packages ship an affected version, including github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server and github.com/mattermost/mattermost-server/v5. It affects 1 product.

Products include Mattermost Mattermost.

How do I fix CVE-2024-29977?

Upgrade github.com/mattermost/mattermost/server/v8 to a fixed version for your release line: 9.5.7 or 9.9.1.

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

Is CVE-2024-29977 being exploited?

There is no known exploitation of CVE-2024-29977 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-jq3g-xqpx-37x3, GO-2024-3030.