This High severity Injection vulnerability was introduced in versions 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center.

This Injection vulnerability, with a CVSS Score of 7 and a CVSS Vector of CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/S:P/AU:N/RE:M/U:Green allows an authenticated attacker to modify the actions taken by a system call.

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

• Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.10
• Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.14

See the release notes (https://confluence.atlassian.com/doc/confluence-release-notes-327.html). You can download the latest version of Confluence Data Center from the download center (https://www.atlassian.com/software/confluence/download-archives).

The National Vulnerability Database provides the following description for this vulnerability: ACE vulnerability in conditional configuration file processing by QOS.CH logback-core up to and including version 1.5.18 in Java applications, allows an attacker to execute arbitrary code by compromising an existing logback configuration file or by injecting an environment variable before program execution.

A successful attack requires the presence of Janino library and Spring Framework to be present on the user's class path. In addition, the attacker must  have write access to a
configuration file. Alternatively, the attacker could inject a malicious
environment variable pointing to a malicious configuration file. In both
cases, the attack requires existing privilege.