Latest Confluence server vulnerability #
An actively exploited zero-day has surfaced in popular wiki software Confluence. Deemed “critical” in severity with a CVSS score of 10 out of 10, this vulnerability affects most supported versions of Confluence Server and Confluence Data Center running 8.0.0 or later. Hosted instances within Atlassian Cloud and versions prior to 8.0.0 are reportedly protected from exploitation.
What is the impact? #
Upon successful exploitation, this vulnerability (tracked as CVE-2023-22515) can provide privilege escalation to external attackers allowing them to exploit the system and create Confluence administrator accounts, allowing for unrestricted access to affected instances.
Are updates available? #
Atlassian has made fixes available and strongly encourages admins to update their hosted instances. If patching in the near term isn't viable, mitigation strategies to limit exploitation opportunities in addition to recommended steps to check for evidence of compromise are also provided. CISA has added this zero-day to its Known Exploited Vulnerabilities Catalog, advising organizations to check for evidence of compromise and reporting any positive findings back to CISA.
How do I find potentially vulnerable Confluence instances with runZero? #
From the Service Inventory, use the following pre-built query to locate assets running Confluence within your network which may need remediation or mitigation:
product:confluence OR (_asset.protocol:http AND protocol:http AND has:http.head.xConfluenceRequestTime)
As always, any prebuilt queries we create are available from our Queries Library. Check out the library for other useful inventory queries.
CVE-2022-26134 (June 2022) #
On June 3rd, 2022, an actively exploited zero-day surfaced in popular wiki software Confluence. Deemed “critical” in severity, this vulnerability affected all supported versions of Confluence Server and Confluence Data Center, and also older, unsupported versions (i.e. everything after version 1.3.0). Hosted instances within Atlassian Cloud were reportedly protected from exploitation.
What was the impact? #
Upon successful exploitation via OGNL template injection, this vulnerability (tracked as CVE-2022-26134) could provide unauthenticated remote code execution (RCE) to an attacker. Cybersecurity firm Volexity discovered the vulnerability while performing incident response, and noted, confirmed, and disclosed the actively exploited attack vector to Atlassian.
Atlassian made fixes available for a number of versions and strongly encouraged admins to update. If patching in the near term wasn’t viable, mitigation strategies to limit exploitation opportunities were also provided. CISA added this zero-day to its Known Exploited Vulnerabilities Catalog, with advice to block internet access to affected Confluence products.
CVE-2021-26084 (September 2021) #
The U.S. Cyber Command reported “mass exploitation” of a code execution vulnerability in Atlassian’s popular Confluence software (CVE-2021-26084). This vulnerability received a CVSS Base score of 9.8 (considered “critical”), required no authentication for exploitation, and affected many on-prem versions of the product (Atlassian said at the time that Confluence Cloud customers were not affected). Public reports of exploitation also surfaced, including a Confluence instance of the Jenkins project compromised for cryptomining purposes.
Atlassian provided fixed versions that on-prem Confluence admins were advised to upgrade to as soon as possible, as well as mitigations for those who could not upgrade immediately. As an aside, there were some interesting events around the leaking of a private exploit PoC during disclosure with a vulnerable party.
