CVE-2012-4359 in Winlog Pro
Summary
by MITRE
Sielco Sistemi Winlog Pro SCADA before 2.07.18 and Winlog Lite SCADA before 2.07.18 do not validate the return value of the realloc function, which allows remote attackers to cause a denial of service (invalid 0x00 write operation and daemon crash) or possibly have unspecified other impact via a port-46824 TCP packet with a crafted negative integer after the opcode. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-4358.
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Analysis
by VulDB Data Team • 04/16/2017
The vulnerability described in CVE-2012-4359 represents a critical memory management flaw in Sielco Sistemi Winlog Pro and Winlog Lite SCADA systems, specifically affecting versions prior to 2.07.18. This issue stems from inadequate input validation within the realloc function implementation, creating a dangerous condition where the software fails to properly handle memory reallocation operations. The flaw manifests when the system receives a specially crafted TCP packet on port 46824, which contains an opcode followed by a negative integer value. This particular vulnerability is classified under CWE-687, which deals with improper handling of memory allocation functions, and more specifically addresses CWE-704, concerning incorrect use of memory allocation functions. The root cause lies in the incomplete remediation of a previous vulnerability, CVE-2012-4358, where developers failed to implement a complete fix for memory handling issues.
The technical exploitation of this vulnerability occurs through a remote attack vector that requires no authentication, making it particularly dangerous in industrial control system environments. When the SCADA system processes the malformed TCP packet, the negative integer value passed to the realloc function causes the system to attempt an invalid memory reallocation operation. This improper handling leads to a write operation at address 0x00, which is typically protected memory space, resulting in a segmentation fault or similar memory access violation. The system daemon crashes immediately upon encountering this invalid write operation, causing a complete denial of service condition that can disrupt critical industrial processes. The vulnerability's impact extends beyond simple denial of service, as the improper memory handling could potentially lead to arbitrary code execution or other unspecified security consequences, making it a serious concern for operational technology environments.
The operational implications of CVE-2012-4359 are particularly severe in industrial automation and control systems where continuous operation is critical. SCADA systems managing power grids, water treatment facilities, or manufacturing processes face significant risk when exposed to this vulnerability, as any disruption can lead to cascading failures across entire industrial operations. The lack of authentication requirements for exploitation means that attackers can remotely compromise these systems from outside the network perimeter, potentially leading to widespread operational disruption. The vulnerability affects systems that rely on the Winlog Pro and Winlog Lite platforms, which are commonly deployed in critical infrastructure sectors where system reliability and security are paramount. Organizations using these SCADA systems must consider the potential for extended downtime and operational losses when this vulnerability is exploited.
Mitigation strategies for CVE-2012-4359 primarily focus on applying the vendor-provided patch that addresses the incomplete fix for CVE-2012-4358. System administrators should immediately upgrade to Winlog Pro and Winlog Lite versions 2.07.18 or later, which contain the proper memory validation mechanisms for realloc function calls. Network segmentation and access control measures should be implemented to limit exposure of port 46824 to only trusted sources, although this approach provides only partial protection since the vulnerability is exploitable remotely. Additional defensive measures include implementing network monitoring to detect anomalous TCP packet patterns on the affected port, deploying intrusion detection systems that can identify crafted negative integer values in SCADA communications, and establishing robust network firewalls that can filter out malicious traffic targeting these specific protocols. Organizations should also conduct thorough vulnerability assessments of their industrial control systems to identify any other potentially affected components that may share similar memory handling flaws. The remediation process must be carefully coordinated with operational requirements to minimize downtime during the patching process, as these systems often operate in environments where immediate system restarts are not feasible.