CVE-2011-3321 in SIMATIC Wincc Runtime
Summary
by MITRE
Heap-based buffer overflow in the Siemens WinCC Runtime Advanced Loader, as used in SIMATIC WinCC flexible Runtime and SIMATIC WinCC (TIA Portal) Runtime Advanced, allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a crafted packet to TCP port 2308.
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Analysis
by VulDB Data Team • 11/20/2021
The vulnerability identified as CVE-2011-3321 represents a critical heap-based buffer overflow within Siemens WinCC Runtime Advanced Loader components, specifically affecting SIMATIC WinCC flexible Runtime and SIMATIC WinCC (TIA Portal) Runtime Advanced implementations. This flaw exists in the network communication handling mechanism that processes incoming packets on TCP port 2308, creating a significant security risk for industrial control systems and automation environments. The vulnerability stems from inadequate input validation and memory management practices within the runtime loader component that processes network traffic from remote attackers.
The technical exploitation of this vulnerability occurs through the manipulation of network packets sent to the designated TCP port 2308, where the WinCC Runtime Advanced Loader fails to properly validate the size and content of incoming data structures. When a specially crafted packet is received, the loader attempts to copy data into a heap-allocated buffer without sufficient bounds checking, resulting in memory corruption that can manifest as either denial of service conditions or potential arbitrary code execution. This type of vulnerability falls under the CWE-121 heap-based buffer overflow category, which is classified as a critical weakness in memory safety that allows attackers to overwrite adjacent memory locations and potentially hijack program execution flow.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential system compromise within industrial environments where Siemens WinCC products are deployed. Attackers leveraging this vulnerability could gain unauthorized access to critical control systems, potentially leading to production disruptions, safety system manipulation, or data integrity compromise. The remote attack vector means that adversaries do not require physical access to the affected systems, making it particularly dangerous for operational technology environments that may lack traditional network segmentation. This vulnerability aligns with ATT&CK technique T1190 for exploiting vulnerabilities in remote services and T1059 for executing commands through compromised systems.
Mitigation strategies for CVE-2011-3321 should include immediate deployment of official Siemens security patches and updates to the affected WinCC Runtime components. Network administrators should implement strict firewall rules to restrict access to TCP port 2308 from trusted sources only, while also considering network segmentation to isolate critical control systems. System monitoring should be enhanced to detect anomalous network traffic patterns on the affected port, and regular security assessments should be conducted to identify any potential exploitation attempts. Organizations should also implement network intrusion detection systems that can identify and alert on malformed packets targeting this specific vulnerability, as well as maintain comprehensive backup and recovery procedures to ensure rapid restoration of affected systems in case of successful exploitation.