Attackers with local access to the medical office computer can escalate their Windows user privileges to NT AUTHORITYSYSTEM by overwriting one of two Elefant service binaries with weak permissions. The default installation directory of Elefant is C:Elefant1 which is writable for all users. In addition, the Elefant installer registers two Firebird database services which are running as “NT AUTHORITYSYSTEM”.
Path: C:Elefant1Firebird_2binfbserver.exe
Path: C:Elefant1Firebird_2binfbguard.exe
Both service binaries are user writable. This means that a local attacker can rename one of the service binaries, replace the service executable with a new executable, and then restart the system. Once the system has rebooted, the new service binary is executed as NT AUTHORITYSYSTEM.
The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges. Privilege management functions can behave in some less-than-obvious ways, and they have different quirks on different platforms. These inconsistencies are particularly pronounced if you are transitioning from one non-root user to another. Signal handlers and spawned processes run at the privilege of the owning process, so if a process is running as root when a signal fires or a sub-process is executed, the signal handler or sub-process will operate with root privileges.