Analysis Summary

Siemens has disclosed a critical security vulnerability, CVE-2024-56336, affecting specific SINAMICS S200 drive systems. This flaw, which has received a CVSS v3.1 score of 9.8 and a CVSS v4.0 score of 9.5, arises from an unlocked bootloader that allows attackers to inject malicious code or install untrusted firmware. The affected devices include those with serial numbers starting with SZVS8, SZVS9, SZVS0, or SZVSN and an FS number of 02. Siemens' advisory (SSA-787280) warns that this security lapse undermines the device’s security architecture, making it a significant risk for industrial environments.

The vulnerability is classified under CWE-287 (Improper Authentication), indicating that the bootloader fails to verify firmware before installation. This makes it highly exploitable, as attackers do not require special privileges or user interaction to compromise the system. With a network-based attack vector and low attack complexity, the flaw could enable unauthorized control over industrial processes, potentially leading to production disruptions, equipment damage, and data theft. Additionally, it could serve as an entry point for attackers to infiltrate broader industrial control networks.

Despite the severity of the issue, Siemens has not yet released a firmware update to patch the vulnerability. Instead, the company advises customers to implement defense-in-depth security measures, including isolating affected devices from public networks, enforcing strict network segmentation, and monitoring for unauthorized access attempts. Siemens also recommends that organizations follow its operational guidelines for industrial security and contact customer service for further support.

Although the Exploit Prediction Scoring System (EPSS) assigns this vulnerability a probability score of 0.09% (41.3 percentile), meaning widespread attacks have not yet been observed, industrial cybersecurity experts stress the need for immediate action. Given the critical role of SINAMICS S200 drives in manufacturing, energy, and infrastructure sectors, organizations should prioritize securing these systems to prevent potential operational and safety threats.

Impact

• Security Bypass

Indicators of Compromise

CVE

• CVE-2024-56336

Affected Vendors

Affected Products

• Siemens SINAMICS S200

Remediation

Refer to Siemens Security Advisory for patch, upgrade or suggested workaround information.

Siemens Security Advisory