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CVE-2021-43840GHSA-XMGJ-5FH3-XJMM

Path traversal in message_bus

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.3.7
None on Exploit-DB, Metasploit or GitHub

Summary

message_bus is a messaging bus for Ruby processes and web clients. In versions prior to 3.3.7 users who deployed message bus with diagnostics features enabled (default off) are vulnerable to a path traversal bug, which could lead to disclosure of secret information on a machine if an unintended user were to gain access to the diagnostic route. The impact is also greater if there is no proxy for your web application as the number of steps up the directories is not bounded. For deployments which uses a proxy, the impact varies. For example, If a request goes through a proxy like Nginx with `merge_slashes` enabled, the number of steps up the directories that can be read is limited to 3 levels. This issue has been patched in version 3.3.7. Users unable to upgrade should ensure that MessageBus::Diagnostics is disabled.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • discourse message_bus

    fixed in 3.3.7

  • message_busRubyGems

    fixed in 3.3.7

References 2

GitHub · discourse/message_bus