CVE-2023-35075 HTML injection via channel autocomplete

What is CVE-2023-35075?

CVE-2023-35075 is a low-severity cross-site scripting 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 use  innerText / textContent when setting the channel name in the webapp during autocomplete, allowing an attacker to inject HTML to a victim's page by create a channel name that is valid HTML. No XSS is possible though.

Weakness: CWE-74

Which versions are affected by CVE-2023-35075?

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

Products include Mattermost Mattermost.

How do I fix CVE-2023-35075?

Upgrade github.com/mattermost/mattermost-server/v6 to 7.8.13 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2023-35075 being exploited?

There is no known exploitation of CVE-2023-35075 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-jcgv-3pfq-j4hr.