In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an authenticated user, and in some instances an unauthenticated user, to execute arbitrary code on a Confluence Server or Data Center instance. The vulnerable endpoints can be accessed by a non-administrator user or unauthenticated user if ‘Allow people to sign up to create their account’ is enabled. To check whether this is enabled go to COG > User Management > User Signup Options. The affected versions are before version 6.13.23, from version 6.14.0 before 7.4.11, from version 7.5.0 before 7.11.6, and from version 7.12.0 before 7.12.5.https://nvd.nist.gov/vuln/detail/CVE-2021-26084
Today, Blue Teamers, we have another injection vulnerability. Code injection is not a new thing for us to encounter. To review, injection vulnerabilities happen on web applications and web sites when an attacker injects code in an input field that allows them to execute commands. In this case, it allows endpoints to be accessed by a non-administrator user or an unauthenticated user. The reference above shows the option that is enabled in Atlassian Confluence that allows this to happen. Turn it off. And update, update, update when available.
Atlassian Confluence is a team workspace, designed to enhance team collaboration and organization. In the era of Covid, teams are looking for ways to collaborate digitally from afar. This specific vulnerability allows unauthenticated OGNL (Object-Graph Navigation Language) code injection on a Confluence Server or even a Data Center instance, ultimately allowing endpoint access. OGNL has the ability to create or change executable code, which can introduce critical security flaws via attackers executing arbitrary code.