In Zammad before 6.3.1, a Ruby gem bundled by Zammad is installed with world-writable file permissions. This allowed a local attacker on the server to modify the gem's files, injecting arbitrary code into Zammad processes (which run with the environment and permissions of the Zammad user).

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-36078
• https://zammad.com/en/advisories/zaa-2024-04