PT-2013-84: Insuffient Entropy in Siemens SIMATIC S7-1500 CPU PLC Vulnerable platformSiemens SIMATIC S7-1500 CPU PLC Version: 1.1.x and earlierLink: http://www.siemens.com/Severity levelSeverity level: High Impact: Session Hijaking, Information Disclosure, Denial of Service Access Vector: Remote CVSS v2: Base Score: 8.3 Vector: (AV:N/AC:M/Au:N/C:P/I:P/A:C)CVE: CVE-2014-2251Platform descriptionSiemens SIMATIC S7-1500 - controllers featuring high efficiency in data processing, integrated technological functions of Motion Control, PID control and the use of high-speed counters..Vulnerability descriptionThe specialists of the Positive Research center have detected an Insuffient Entropy vulnerability in Siemens SIMATIC S7-1500 CPU PLC.Due to low entropy in its random number generator, the authentication of the integrated web server (port 80/tcp and port 443/tcp) of S7-1500 PLCs might allow attackers to hijack web sessions over the network without authentication.How to fixUpdate your firmware up to the latest versionAdvisory status 05.08.2013 - Vendor gets vulnerability details 12.03.2014 - Vendor releases fixed version and details 25.03.2014 - Public disclosureCreditsThe vulnerability was detected by Alexey Osipov and Alexander Timorin, Positive Research Center (Positive Technologies Company)Referenceshttp://en.securitylab.ru/lab/PT-2013-84 http://www.siemens.com/innovation/pool/de/forschungsfelder/siemens_security_advisory_ssa-456423.pdf https://ics-cert.us-cert.gov/advisories/ICSA-14-073-01 Reports on the vulnerabilities previously discovered by Positive Research:http://www.ptsecurity.com/research/advisory/ http://en.securitylab.ru/lab/
