A vulnerability has been identified in SINUMERIK 808D V4.7 (All versions), SINUMERIK 808D V4.8 (All versions), SINUMERIK 828D V4.7 (All versions < V4.7 SP6 HF1), SINUMERIK 840D sl V4.7 (All versions < V4.7 SP6 HF5), SINUMERIK 840D sl V4.8 (All versions < V4.8 SP3). A local attacker with elevated user privileges (manufact) could modify a CRAMFS archive so that after reboot the system loads the modified CRAMFS file and attacker-controlled code is executed with root privileges. The security vulnerability could be exploited by an attacker with local access to the affected systems. Successful exploitation requires elevated user privileges (manufact) but no user interaction. The vulnerability could allow an attacker to compromise confidentiality, integrity and availability of the system. At the time of advisory publication no public exploitation of this security vulnerability was known.