Vulnerability identifier: #VU34219

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-21257

CWE-ID: CWE-862

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mattermost Server
Client/Desktop applications / Messaging software

Vendor: Mattermost, Inc.

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Mattermost Server: 5.0.0 - 5.0.3

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External links
http://mattermost.com/security-updates/

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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.