Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Synapse and Sydent - CVE-2019-11842
Published: May 17, 2023
Vulnerability identifier: #VU76258
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-11842
CWE-ID: CWE-338
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to gain unauthorized access to the application.
The vulnerability exists due to usage of a weak algorithm to generate a Sydent authentication token or a Synapse random ID. A remote attacker can brute-force the token and gain unauthorized access to the application.
Affected software
Synapse
Sydent
Ubuntu
matrix-synapse (Ubuntu package)
Sydent
Ubuntu
matrix-synapse (Ubuntu package)
How to mitigate CVE-2019-11842
Install updates from vendor's website.
Synapse - update to 0.99.3.1
Sydent - update to 1.0.3
matrix-synapse (Ubuntu package) - update to Ubuntu Pro
Sydent - update to 1.0.3
matrix-synapse (Ubuntu package) - update to Ubuntu Pro