CVE-2021-37859 Reflected XSS in OAuth Flow
Attackers can execute arbitrary scripts in victim browsers via reflected XSS in the OAuth flow of Mattermost instances.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-37859?
CVE-2021-37859 is a high-severity cross-site scripting vulnerability in Mattermost Mattermost, published on 5 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Fixed a bypass for a reflected cross-site scripting vulnerability affecting OAuth-enabled instances of Mattermost.
Weakness: CWE-79
Which versions are affected by CVE-2021-37859?
It affects 1 product.
Products include Mattermost Mattermost.
How do I fix CVE-2021-37859?
No fix has been published for CVE-2021-37859 yet. Limit exposure of the affected software until one is available.
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-2021-37859 being exploited?
There is no known exploitation of CVE-2021-37859 in the wild and no public exploit code.
Other vulnerabilities in Mattermost Mattermost
- CVE-2019-20851 Path traversal in n/a
- CVE-2024-39274 Malicious remote can add users to arbitrary teams and channels
- CVE-2024-39777 Malicious remote can invite itself to an arbitrary local channel
- CVE-2024-39830 Timing attack during remote cluster token comparison when shared channels are enabled
- CVE-2023-3615 Lack of server certificate validation in websockets connection
Sources
Also known as GHSA-r4f6-w245-8wv4.