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CVE-2017-18883: Mattermost Server: Insufficient Entropy
CVE-2017-18883 is rated critical with a CVSS v3.1 base score of 9.1 and affects Mattermost Server. Per its scoring, it can be exploited over the network, without authentication, without any user interaction.
Vulnerability description
An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2, when serving as an OAuth 2.0 Service Provider. There is low entropy for authorization data.
Severity breakdown
CVSS v3.1 9.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
- Attack complexity: Low. No special conditions; the attack can be repeated reliably.
- Privileges required: None. No account or prior access is needed.
- User interaction: None. No action from any user is needed.
- Scope: Unchanged. Impact stays within the vulnerable component.
- Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
- Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
- Availability impact: None. No effect on availability.
Underlying weakness
CWE-331: Insufficient Entropy
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.
Affected products
- Mattermost Server: before 4.1.2; from 4.2.0 before 4.2.1; 4.3.0 rc1; 4.3.0 rc2; 4.3.0 rc3; 4.3.0 rc4