CVE-2008-2111 in Yahoo Assistant
Summary
by MITRE
The ActiveX Control (yNotifier.dll) in Yahoo! Assistant 3.6 and earlier allows remote attackers to execute arbitrary code via unspecified vectors in the Ynoifier COM object that trigger memory corruption.
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Analysis
by VulDB Data Team • 05/31/2025
The vulnerability identified as CVE-2008-2111 represents a critical security flaw within the Yahoo Assistant framework. The flaw stems from improper memory management practices within the ActiveX control implementation, creating opportunities for remote code execution attacks that can compromise the affected system. The vulnerability is particularly concerning as it affects a widely deployed software component that many users would have installed on their systems, making it a prime target for exploitation.
The technical implementation of this vulnerability involves memory corruption issues within the Ynoifier COM object that occurs when processing certain input parameters or method calls. The ActiveX control fails to properly validate or sanitize data passed to its internal memory structures, leading to potential buffer overflows, heap corruption, or other memory-related vulnerabilities. Attackers can leverage this weakness by crafting malicious input that triggers the vulnerable code path within the yNotifier.dll component, potentially causing the execution of arbitrary code with the privileges of the affected user. This type of vulnerability falls under the category of heap-based buffer overflow attacks and demonstrates poor defensive programming practices that are commonly addressed through secure coding guidelines.
The operational impact of CVE-2008-2111 extends beyond simple code execution capabilities, as it represents a significant threat vector for attackers seeking to establish persistent access to compromised systems. The vulnerability can be exploited through various attack vectors including web-based delivery mechanisms, where a malicious webpage containing crafted ActiveX controls can automatically trigger the exploit when viewed by an unsuspecting user. This attack surface is particularly dangerous because many users would have the Yahoo! Assistant software installed, and the ActiveX control would be automatically registered and available for use. The exploitation of this vulnerability can lead to complete system compromise, allowing attackers to install additional malware, steal sensitive information, or establish backdoor access for future exploitation attempts.
Mitigation strategies for this vulnerability require immediate action from system administrators and users to address the exposed threat. The primary recommendation involves uninstalling or disabling the vulnerable Yahoo! Assistant software component, as the vendor has not provided a patch for this specific vulnerability due to its age. Organizations should implement browser security policies that prevent automatic execution of ActiveX controls and consider deploying application whitelisting solutions to restrict execution of known vulnerable components. From a defensive perspective, this vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a classic example of improper input validation that violates secure coding practices. The attack pattern described corresponds to techniques found in the MITRE ATT&CK framework under the T1195.002 sub-technique for "Phishing with Spoofed Credentials" and T1059.007 for "Command and Scripting Interpreter: PowerShell," though the original exploit mechanism is more directly related to ActiveX-based exploitation patterns. System hardening measures should include disabling ActiveX controls in web browsers, implementing strict security policies, and conducting regular vulnerability assessments to identify and remediate similar legacy components that may present similar risks.