This High severity Third-Party Dependency vulnerability was introduced in versions 5.1.0, 5.2.0, and 5.3.0 of Crowd Data Center and Server.

This Third-Party Dependency vulnerability, with a CVSS Score of 7.5 and a CVSS Vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N allows an unauthenticated attacker to expose assets in your environment susceptible to exploitation which has high impact to confidentiality, no impact to integrity, no impact to availability, and requires no user interaction.

Atlassian recommends that Crowd Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

• Crowd Data Center and Server 5.3: Upgrade to a release greater than or equal to 5.3.6

See the release notes (https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html). You can download the latest version of Crowd Data Center and Server from the download center (https://www.atlassian.com/software/crowd/download-archive).

The National Vulnerability Database provides the following description for this vulnerability: Applications serving static resources through the functional web frameworks WebMvc.fn or WebFlux.fn are vulnerable to path traversal attacks. An attacker can craft malicious HTTP requests and obtain any file on the file system that is also accessible to the process in which the Spring application is running.

Specifically, an application is vulnerable when both of the following are true:

• the web application uses RouterFunctions to serve static resources
• resource handling is explicitly configured with a FileSystemResource location

However, malicious requests are blocked and rejected when any of the following is true:

• the Spring Security HTTP Firewall https://docs.spring.io/spring-security/reference/servlet/exploits/firewall.html  is in use
• the application runs on Tomcat or Jetty