Mattermost fails to check if a custom emoji reaction exists when sending it to a post and to limit the amount of custom emojis allowed to be added in a post, allowing an attacker sending a huge amount of non-existent custom emojis in a post to crash the mobile app of a user seeing the post and to crash the server due to overloading when clients attempt to retrive the aforementioned post. 

Advisories
Source ID Title
EUVD EUVD EUVD-2024-0474 Mattermost vulnerable to denial of service via large number of emoji reactions
Github GHSA Github GHSA GHSA-32h7-7j94-8fc2 Mattermost vulnerable to denial of service via large number of emoji reactions
Fixes

Solution

Update Mattermost Server to versions 9.3.0, 9.2.4, 9.1.5, 8.1.8 or higher.


Workaround

No workaround given by the vendor.

References
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2024-08-01T18:40:20.579Z

Reserved: 2024-02-09T14:53:28.621Z

Link: CVE-2024-1402

cve-icon Vulnrichment

Updated: 2024-08-01T18:40:20.579Z

cve-icon NVD

Status : Modified

Published: 2024-02-09T16:15:07.880

Modified: 2024-11-21T08:50:30.447

Link: CVE-2024-1402

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.