CVE-2007-4145 in BlueSkychat
Summary
by MITRE
Heap-based buffer overflow in the BlueSkychat (BlueSkyCat) ActiveX control (V2.V2Ctrl.1) in v2.ocx 8.1.2.0 and earlier allows remote attackers to execute arbitrary code via a long string in the second argument to the ConnecttoServer method.
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Analysis
by VulDB Data Team • 07/21/2021
The vulnerability identified as CVE-2007-4145 represents a critical heap-based buffer overflow in the BlueSkychat ActiveX control component known as V2Ctrl. This flaw exists within the v2.ocx library version 8.1.2.0 and earlier releases, making it a significant security concern for systems that utilize this ActiveX control for instant messaging and chat functionalities. The vulnerability specifically affects the ConnecttoServer method which processes user input through its second parameter, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code on affected systems.
This heap-based buffer overflow occurs when the BlueSkychat ActiveX control fails to properly validate the length of input data passed to the ConnecttoServer method. The control allocates a fixed-size buffer in heap memory to store the second argument provided to this method, but does not perform adequate bounds checking before copying the input data. When an attacker provides a string that exceeds the allocated buffer size, the excess data overflows into adjacent memory locations, potentially overwriting critical program structures including return addresses and function pointers. This type of vulnerability falls under CWE-121, which specifically addresses heap-based buffer overflow conditions that can lead to arbitrary code execution.
The operational impact of this vulnerability extends beyond simple code execution, as it can be exploited to gain complete control over affected systems. Attackers can craft malicious input strings that overwrite memory contents to redirect program execution flow to malicious payloads. The ActiveX control's widespread deployment in enterprise environments and public-facing applications creates a substantial attack surface, particularly when systems have default installations or when users are unable to disable ActiveX controls. This vulnerability aligns with ATT&CK technique T1190, which describes the exploitation of vulnerabilities in software components to achieve remote code execution.
Mitigation strategies for CVE-2007-4145 should focus on immediate remediation through software updates from the vendor, as well as defensive measures such as disabling the problematic ActiveX control in web browsers and implementing application whitelisting policies. Organizations should also consider network segmentation and monitoring for suspicious network traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and proper memory management in software development practices, particularly for components that process untrusted data from external sources. Additionally, system administrators should ensure that all ActiveX controls are regularly updated and that users are educated about the risks associated with enabling potentially vulnerable components in their browser environments.