Active Exploitation of Cyber Vulnerability

The Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), and Multi-State Information Sharing and Analysis Center (MS-ISAC) released this Joint Cybersecurity Advisory in response to the active exploitation of CVE-2023-22515 . This recently disclosed vulnerability affects certain versions of Atlassian Confluence Data Center and Server, enabling malicious cyber threat actors to obtain initial access to Confluence instances by creating unauthorized Confluence administrator accounts. Threat actors exploited CVE-2023-22515 as a zero-day to obtain access to victim systems and continue active exploitation post-patch. Atlassian has rated this vulnerability as critical; CISA, FBI, and MS-ISAC expect widespread, continued exploitation due to ease of exploitation.
CISA, FBI, and MS-ISAC strongly encourage network administrators to immediately apply the upgrades provided by Atlassian. CISA, FBI, and MS-ISAC also encourage organizations to hunt for malicious activity on their networks using the detection signatures and indicators of compromise (IOCs) contained in this advisory. If a potential compromise is detected, organizations should apply the incident response recommendations found in this advisory.
For additional information on upgrade instructions, a complete list of affected product versions, and IOCs, see Atlassian’s security advisory for CVE-2023-22515. While Atlassian’s advisory provides interim measures to temporarily mitigate known attack vectors, CISA, FBI, and MS-ISAC strongly encourage upgrading to a fixed version or taking servers offline to apply necessary updates.