A high-severity vulnerability in Atlassian Confluence Data Center and Server can be exploited to execute arbitrary code remotely.
Tracked as CVE-2024-21683 (CVSS score of 8.3), the remote code execution (RCE) bug is rooted in the input validation mechanism of the function that allows users to add a new code block macro language definition.
“Insufficient validation allows the authenticated attacker to inject malicious Java code embedded in a file,” cybersecurity firm SonicWall warns in a technical writeup.
Successful exploitation of the bug, however, requires that the attacker has the privileges required for adding new macro languages, and to upload a malicious language file using the ‘Add a new language’ function in the ‘Configure Code Macro’ section.
According to Atlassian, which rolled out patches for the vulnerability a couple of weeks ago, the issue was introduced in Confluence version 5.2.
“The exploitation of this vulnerability yields the remote threat actor the ability to execute arbitrary code on the server. It has a high impact on the confidentiality, integrity and availability of the system and does not require user interaction,” SonicWall warns.
The vulnerability impacts all Confluence Data Center versions from 5.2 to 8.9.0 and was addressed with the release of versions 8.9.1, 8.5.9 LTS, and 7.19.22 LTS of the product. The updates resolve four other vulnerabilities in Confluence and third-party dependencies.
While Atlassian makes no mention of the bug being exploited in the wild, threat actors have been observed targeting Confluence vulnerabilities shortly after disclosure.
CVE-2024-21683 too could soon be exploited in attacks, as proof-of-concept (PoC) code targeting it was released shortly after patches started rolling out and technical details on the bug are also available.
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