QID 379556

Bitbucket Data Center looks like a single instance of Bitbucket Server to users, but under the hood, it consists of a cluster of multiple machines ("cluster nodes") each running the Bitbucket Server web application, behind a load balancer.

CVE-2021-46877: Affected jackson-databind allows attackers to cause a denial of service (2 GB transient heap usage per read) in uncommon situations involving JsonNode JDK serialization.

Affected version:
7.21.x: prior to 7.21.14
7.17.0 to 7.17.21
8.7.0 to 8.7.5
8.8.0 to 8.8.7
8.9.x: prior to 8.9.4
8.10.x: prior to 8.10.4
8.11.x: prior to 8.11.3
8.12.x: prior to 8.12.1
8.13.x: prior to 8.13.1

QID Detection Logic(Unauthenticated):
The QID checks for vulnerable versions of Atlassian Bitbucket Server by sending a GET request to /login endpoint.


QID Detection Logic:(Authenticated)
The QID checks for vulnerable versions of Atlassian Bitbucket Server by checking the registry entry for windows and invoking commands in linux.

Note: Here, we are not checking actual version of jackson-databind Third-Party Dependency. Hence, QID set as practice.

Successful exploitation of this vulnerability allows denial or disruption of service.