CVE-2021-43799

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Summary

CVECVE-2021-43799
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2022-01-25 21:15:00 UTC
Updated2022-02-02 18:35:00 UTC
DescriptionZulip 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.

Risk And Classification

Problem Types: CWE-338

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Zulip Zulip All All All All

References

ReferenceSourceLinkTags
RabbitMQ exposes ports with weak default secrets · Advisory · zulip/zulip · GitHub CONFIRM github.com
Release Zulip Server 4.9 · zulip/zulip · GitHub MISC github.com
GitHub - gteissier/erl-matter: Erlang distribution weaknesses and tooling MISC github.com
CVE-2021-43799: Set a secure Erlang cookie. · zulip/zulip@a5496f4 · GitHub MISC github.com
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NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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