CVE-2006-3298 in Yahoo!
Summary
by MITRE
Yahoo! Messenger 7.5.0.814 and 7.0.438 allows remote attackers to cause a denial of service (crash) via messages that contain non-ASCII characters, which triggers the crash in jscript.dll.
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Analysis
by VulDB Data Team • 07/13/2019
The vulnerability identified as CVE-2006-3298 represents a critical denial of service flaw affecting Yahoo! Messenger versions 7.5.0.814 and 7.0.438. This security issue stems from improper handling of character encoding within the messaging application's processing pipeline. The flaw specifically manifests when the application receives messages containing non-ascii characters, which are then processed through the jscript.dll component. This particular dynamic link library serves as a crucial element in the application's scripting engine and is responsible for executing various client-side operations. When malformed message content containing extended character sets reaches the application, the jscript.dll module fails to properly sanitize or validate these inputs, leading to abrupt termination of the messenger process. The vulnerability operates at the application layer and demonstrates a classic buffer overflow or memory corruption issue that has been categorized under CWE-121 as a buffer overflow in heap-based memory allocation. This flaw effectively allows remote attackers to execute a denial of service attack without requiring any privileged access or authentication credentials, making it particularly dangerous in enterprise environments where instant messaging systems are heavily utilized.
The operational impact of this vulnerability extends beyond simple service disruption, as it creates potential for widespread communication interruption within organizations that rely on Yahoo Messenger, indicating a systemic issue within the application's input validation mechanisms rather than a localized bug. Network administrators and security professionals must consider this vulnerability when assessing their organization's attack surface, particularly in environments where legacy messaging systems remain in use. The crash behavior typically results in immediate application termination without proper cleanup of resources, potentially leading to additional system instability if the application is part of a larger communication infrastructure.
Mitigation strategies for CVE-2006-3298 should prioritize immediate patching and system hardening measures. Organizations should implement network monitoring to detect unusual message patterns that may indicate exploitation attempts, particularly focusing on traffic containing non-ascii character sequences. The most effective remediation involves upgrading to patched versions of Yahoo! Messenger or transitioning to more modern communication platforms that have addressed such vulnerabilities. System administrators should also consider implementing network segmentation to limit the potential impact of such attacks, ensuring that the messenger application does not have unrestricted access to critical network resources. Input validation should be strengthened at multiple layers, including application-level filtering of character sets and implementing proper error handling mechanisms within the jscript.dll processing pipeline. Security teams should also establish incident response procedures specifically addressing application crashes and denial of service conditions, ensuring rapid identification and containment of potential exploitation attempts. Additional defensive measures include deploying intrusion detection systems that can identify suspicious message content patterns and implementing regular security assessments to identify similar vulnerabilities in other legacy applications. The vulnerability serves as a reminder of the importance of proper input validation and the critical need for maintaining up-to-date security patches across all enterprise applications. Organizations should also consider transitioning away from legacy messaging platforms that no longer receive security updates, as these systems often contain multiple unpatched vulnerabilities that can serve as entry points for broader network attacks.