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CVE-2021-43799

Common vulnerabilities & exposures (CVE)

CVE databaseCVE database blogpostRelease & EoL database
 
Published at: - 25-01-2022 10:15
Last modified: - 02-02-2022 07:35
Total changes: - 3

Description

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.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Low
Attack complexity
Network
Attack vector
High
Availability
High
Confidentiality
High
Integrity
None
Privileges required
Unchanged
Scope
None
User interaction
9.8
Base score
3.9
5.9
Exploitability score
Impact score
 

Verification logic

OR
vendor=zulip AND product=zulip AND versionEndExcluding=4.9
 

Reference

 


Keywords

NVD

 

CVE-2021-43799

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures

 

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