CVE-2021-43799 RabbitMQ exposes ports with weak default secrets in Zulip Server
Weak default secrets in RabbitMQ allow remote attackers to brute-force access, leading to arbitrary code execution and data theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-43799?
CVE-2021-43799 is a high-severity vulnerability in zulip, published on 25 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-338
Which versions are affected by CVE-2021-43799?
It affects 1 product.
Products include Zulip Zulip.
How do I fix CVE-2021-43799?
No fix has been published for CVE-2021-43799 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-43799 being exploited?
There is no known exploitation of CVE-2021-43799 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in zulip
- CVE-2022-35962 Crafted link in Zulip message can cause disclosure of credentials
- CVE-2016-4427 Auth bypass in zulip
- CVE-2021-3866 Cross-site Scripting (XSS) - Stored in zulip/zulip
- CVE-2023-28623 Unauthorized user can register an account in specific configurations in Zulip
- CVE-2021-43791 Ineffective expiration validation for invitation links in Zulip
Sources
Also known as GHSA-p663-wxvv-2fjp.