title: Ephemeral messages return private channel contents in permalink previews
description: Mattermost fails to sanitize ephemeral error messages, allowing an attacker to obtain arbitrary message contents by a specially crafted /groupmsg command.
problem types: CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
affected:
{
defaultStatus: unaffected
product: Mattermost
vendor: Mattermost
versions:
lessThanOrEqual: 7.1.9, status: affected, version: 0, versionType: semver
lessThanOrEqual: 7.8.4, status: affected, version: 0, versionType: semver
lessThanOrEqual: 7.9.3, status: affected, version: 0, versionType: semver
status: affected, version: 7.10.0
status: unaffected, version: 7.1.10
status: unaffected, version: 7.9.4
status: unaffected, version: 7.8.5
status: unaffected, version: 7.10.1
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
version: 3.1
]
format: CVSS
scenarios: GENERAL
solutions: Update Mattermost to version 7.1.10, 7.8.5, 7.9.4, 7.10.1 or higher