This High severity RCE (Remote Code Execution) vulnerability was introduced in version 4.9.0 of Crucible Server.

This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 8.7 and a CVSS Vector of CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N allows an unauthenticated attacker to execute arbitrary code.

Atlassian recommends that Crucible Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

• Crucible Server 4.9: Upgrade to a release greater than or equal to 4.9.12

See the release notes (https://confluence.atlassian.com/crucible/crucible-releases-298977378.html). You can download the latest version of Crucible Data Center and Server from the download center (https://www.atlassian.com/software/crucible/download-archives).

The National Vulnerability Database provides the following description for this vulnerability: Any project that parses untrusted Protocol Buffers data containing an arbitrary number of nested groups / series of SGROUP tags can corrupted by exceeding the stack limit i.e. StackOverflow. Parsing nested groups as unknown fields with DiscardUnknownFieldsParser or Java Protobuf Lite parser, or against Protobuf map fields, creates unbounded recursions that can be abused by an attacker.