Denial of service in Mattermost Server

1) Race condition

EUVDB-ID: #VU51610

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper handling of WebSockets closing. A remote attacker can exploit the race and cause a denial of service condition on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Mattermost Server: 5.0.0 - 5.33.0

External links

http://docs.mattermost.com/administration/changelog.html#release-v5-33-feature-release
http://mattermost.atlassian.net/browse/MM-33233

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.