title: Excessive resource consumption when sending long emoji names in user custom status
description: Mattermost fails to properly validate the length of the emoji value in the custom user status, allowing an attacker to send multiple times a very long string as an emoji value causing high resource consumption and possibly crashing the server.
problem types: CWE-400: Uncontrolled Resource Consumption
affected:
{
defaultStatus: unaffected
product: Mattermost
vendor: Mattermost
versions:
lessThanOrEqual: 9.2.4, status: affected, version: 0, versionType: semver
lessThanOrEqual: 8.1.8, status: affected, version: 0, versionType: semver
lessThanOrEqual: 9.3.0, status: affected, version: 0, versionType: semver
status: unaffected, version: 9.4.0
status: unaffected, version: 9.3.1
status: unaffected, version: 9.2.5
status: unaffected, version: 8.1.9
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 4.3
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
version: 3.1
]
format: CVSS
scenarios: GENERAL
solutions: Update Mattermost Server to versions 9.4.0, 9.3.1, 9.2.5, 8.1.9 or higher.