CVE-2021-43840

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.
Configurations

Configuration 1 (hide)

cpe:2.3:a:discourse:message_bus:*:*:*:*:*:ruby:*:*

History

29 Dec 2021, 18:39

Type Values Removed Values Added
CVSS v2 : unknown
v3 : 4.4
v2 : 3.5
v3 : 6.5
CPE cpe:2.3:a:discourse:message_bus:*:*:*:*:*:ruby:*:*
First Time Discourse
Discourse message Bus
References (CONFIRM) https://github.com/discourse/message_bus/security/advisories/GHSA-xmgj-5fh3-xjmm - (CONFIRM) https://github.com/discourse/message_bus/security/advisories/GHSA-xmgj-5fh3-xjmm - Third Party Advisory
References (MISC) https://github.com/discourse/message_bus/commit/9b6deee01ed474c7e9b5ff65a06bb0447b4db2ba - (MISC) https://github.com/discourse/message_bus/commit/9b6deee01ed474c7e9b5ff65a06bb0447b4db2ba - Patch, Third Party Advisory

17 Dec 2021, 19:42

Type Values Removed Values Added
New CVE

Information

Published : 2021-12-17 19:15

Updated : 2023-12-10 14:09


NVD link : CVE-2021-43840

Mitre link : CVE-2021-43840

CVE.ORG link : CVE-2021-43840


JSON object : View

Products Affected

discourse

  • message_bus
CWE
CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')