Malicious actors are taking advantage of a critical security flaw in Atlassian Confluence Data Center and Confluence Server, which was recently disclosed. Tracked as CVE-2023-22527, the vulnerability affects outdated versions of the software, allowing unauthenticated attackers to execute remote code on vulnerable installations. Within three days of the flaw’s public disclosure, there have been nearly 40,000 exploitation attempts recorded from over 600 unique IP addresses. The attackers, mainly from Russia, are currently engaged in testing callback attempts and ‘whoami’ execution, indicating opportunistic scanning for vulnerable servers.
The security flaw, CVE-2023-22527, is considered critical, as it enables unauthenticated attackers to inject Object-Graph Navigation Language (OGNL) expressions into the Confluence instance. This injection capability allows the execution of arbitrary code and system commands. ProjectDiscovery researchers emphasized the severity of the vulnerability, highlighting its potential impact on Atlassian’s Confluence Server and Data Center. The flaw affects Confluence Data Center and Server 8 versions released before December 5, 2023, including version 8.4.5.
As of January 21, 2024, over 11,000 Atlassian instances were found accessible over the internet, although the exact number vulnerable to CVE-2023-22527 remains unknown. The exploitation attempts are not limited to any specific region, with Russia having the highest number of attacker IP addresses. The ongoing exploitation underscores the urgency for organizations using Atlassian Confluence to promptly update their systems to secure versions, mitigating the risk of unauthorized remote code execution.