VDB-157051 · CVE-2018-21256 · GCVE-0-2018-21256

Mattermost Server up to 5.0 Access Restriction Command permission assignment

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.1	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in Mattermost Server up to 5.0. This issue affects some unknown processing of the component Access Restriction. This manipulation as part of Command causes permission assignment. This vulnerability is handled as CVE-2018-21256. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Mattermost Server up to 5.0. Affected by this vulnerability is some unknown processing of the component Access Restriction. The manipulation as part of a Command leads to a permission assignment vulnerability. The CWE definition for the vulnerability is CWE-732. The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for group-message channel creation) via the Group message slash command.

The weakness was released 06/19/2020 (Website). It is possible to read the advisory at mattermost.com. This vulnerability is known as CVE-2018-21256 since 06/19/2020. The exploitation appears to be easy. The attack can be launched remotely. Required for exploitation is a single authentication. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 5.1 eliminates this vulnerability.

Entries connected to this vulnerability are available at VDB-156956, VDB-156957, VDB-156958 and VDB-156959. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Groupware Software

Name

Mattermost Server

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.3
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Permission assignment
CWE: CWE-732 / CWE-275 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Mattermost Server 5.1

Timelineinfo

06/19/2020 🔍
06/19/2020 +0 days 🔍
06/21/2020 +2 days 🔍
10/26/2020 +127 days 🔍

Sourcesinfo

Advisory: mattermost.com
Status: Not defined
Confirmation: 🔍

CVE: CVE-2018-21256 (🔍)
GCVE (CVE): GCVE-0-2018-21256
GCVE (VulDB): GCVE-100-157051
See also: 🔍

Entryinfo

Created: 06/21/2020 09:21
Updated: 10/26/2020 07:38
Changes: 06/21/2020 09:21 (40), 06/21/2020 09:26 (17), 10/26/2020 07:38 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.