Vulnerabilities > CVE-2021-43799 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerability in Zulip

CVSS 9.8 - CRITICAL

Attack vector

NETWORK

Attack complexity

LOW

Privileges required

NONE

Confidentiality impact

HIGH

Integrity impact

HIGH

Availability impact

HIGH

network

low complexity

zulip

CWE-338

critical

NVD

Published: 2022-01-25

Updated: 2024-11-21

Summary

Zulip is an open-source team collaboration tool. Zulip Server installs RabbitMQ for internal message passing. In versions of Zulip Server prior to 4.9, the initial installation (until first reboot, or restart of RabbitMQ) does not successfully limit the default ports which RabbitMQ opens; this includes port 25672, the RabbitMQ distribution port, which is used as a management port. RabbitMQ's default "cookie" which protects this port is generated using a weak PRNG, which limits the entropy of the password to at most 36 bits; in practicality, the seed for the randomizer is biased, resulting in approximately 20 bits of entropy. If other firewalls (at the OS or network level) do not protect port 25672, a remote attacker can brute-force the 20 bits of entropy in the "cookie" and leverage it for arbitrary execution of code as the rabbitmq user. They can also read all data which is sent through RabbitMQ, which includes all message traffic sent by users. Version 4.9 contains a patch for this vulnerability. As a workaround, ensure that firewalls prevent access to ports 5672 and 25672 from outside the Zulip server.

Vulnerable Configurations

Part	Description	Count
Application	Zulip Zulip Zulip - Zulip Zulip 0.7.1 Zulip Zulip 1.0.11 Zulip Zulip 1.0.12 Zulip Zulip 1.0.13 Zulip Zulip 1.0.14 Zulip Zulip 1.0.15 Zulip Zulip 1.0.16 Zulip Zulip 1.0.17 Zulip Zulip 1.0.18 Zulip Zulip 1.0.19 Zulip Zulip 1.0.20 Zulip Zulip 1.0.21 Zulip Zulip 1.0.22 Zulip Zulip 1.0.24 Zulip Zulip 1.0.25 Zulip Zulip 1.0.26 Zulip Zulip 1.0.27 Zulip Zulip 1.0.29 Zulip Zulip 1.3.0 Zulip Zulip 1.3.1 Zulip Zulip 1.3.2 Zulip Zulip 1.3.3 Zulip Zulip 1.3.4 Zulip Zulip 1.3.5 Zulip Zulip 1.3.6 Zulip Zulip 1.3.7 Zulip Zulip 1.3.8 Zulip Zulip 1.3.9 Zulip Zulip 1.3.10 Zulip Zulip 1.3.11 Zulip Zulip 1.3.12 Zulip Zulip 1.3.13 Zulip Zulip 1.4.0 Zulip Zulip 1.4.1 Zulip Zulip 1.4.2 Zulip Zulip 1.4.3 Zulip Zulip 1.5.0 Zulip Zulip 1.5.1 Zulip Zulip 1.5.2 Zulip Zulip 1.6.0 Zulip Zulip 1.7.0 Zulip Zulip 1.7.1 Zulip Zulip 1.7.2 Zulip Zulip 1.8.0 Zulip Zulip 1.8.1 Zulip Zulip 1.9.0 Zulip Zulip 1.9.1 Zulip Zulip 1.9.2 Zulip Zulip 2.0.0 Zulip Zulip 2.0.1 Zulip Zulip 2.0.2 Zulip Zulip 2.0.3 Zulip Zulip 2.0.4 Zulip Zulip 2.0.5 Zulip Zulip 2.0.6 Zulip Zulip 2.0.7 Zulip Zulip 2.0.8 Zulip Zulip 2.1.0 Zulip Zulip 2.1.1 Zulip Zulip 2.1.2 Zulip Zulip 2.1.3 Zulip Zulip 2.1.4 Zulip Zulip 2.1.5 Zulip Zulip 2.1.6 Zulip Zulip 2.1.7 Zulip Zulip 2.1.8 Zulip Zulip 2.1.33 Zulip Zulip 2.2 Zulip Zulip 2.3.35 Zulip Zulip 2.7.39 Zulip Zulip 3.0 Zulip Zulip 3.0.40 Zulip Zulip 3.1 Zulip Zulip 3.1.41 Zulip Zulip 3.2 Zulip Zulip 3.2.42 Zulip Zulip 3.3 Zulip Zulip 3.3.43 Zulip Zulip 3.4 Zulip Zulip 4.0 Zulip Zulip 4.1 Zulip Zulip 4.2 Zulip Zulip 4.3 Zulip Zulip 4.4 Zulip Zulip 4.5 Zulip Zulip 4.6 Zulip Zulip 4.7 Zulip Zulip 4.8	128

Common Weakness Enumeration (CWE)

CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Summary

Vulnerable Configurations

Common Weakness Enumeration (CWE)

References