CVE-2013-0074 in Silverlight
Summary
by MITRE
Microsoft Silverlight 5, and 5 Developer Runtime, before 5.1.20125.0 does not properly validate pointers during HTML object rendering, which allows remote attackers to execute arbitrary code via a crafted Silverlight application, aka "Silverlight Double Dereference Vulnerability."
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2013-0074 represents a critical double dereference flaw within Microsoft Silverlight 5 and its Developer Runtime versions prior to 5.1.20125.0. This issue stems from inadequate pointer validation during HTML object rendering processes, creating a pathway for remote code execution attacks that can be exploited by malicious actors without user interaction. The vulnerability specifically affects the Silverlight runtime environment that enables rich internet applications and multimedia content delivery within web browsers.
The technical implementation of this vulnerability involves a classic double dereference condition where the Silverlight runtime fails to properly validate memory pointers when processing HTML objects embedded within web pages. This flaw occurs during the rendering phase of Silverlight applications, where the runtime attempts to access memory locations through pointers that have not been adequately validated for safety. When attackers craft malicious Silverlight applications with specifically designed pointer sequences, they can manipulate the runtime's memory access patterns to execute arbitrary code with the privileges of the Silverlight application. This type of vulnerability maps directly to CWE-476 which describes NULL pointer dereference conditions, though the double dereference aspect adds complexity to the exploitation vector.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Silverlight applications for business-critical operations. The remote exploitation capability means that attackers can compromise systems simply by delivering malicious content through web browsers without requiring any user interaction or specific system compromise. This makes the vulnerability particularly dangerous in enterprise environments where Silverlight applications may be widely deployed across multiple systems and user endpoints. The impact extends beyond individual system compromise to potential lateral movement within networks and escalation of privileges, as Silverlight applications typically run with elevated permissions to access system resources.
The attack surface for this vulnerability encompasses any web environment that hosts Silverlight applications or displays Silverlight content, including corporate intranets, customer portals, and web-based training platforms. Organizations utilizing Microsoft Silverlight for rich media applications, business intelligence dashboards, or interactive web content are particularly at risk. The vulnerability can be exploited through various attack vectors including malicious websites, compromised web servers, or even through social engineering techniques that trick users into visiting malicious sites hosting crafted Silverlight content.
Security professionals should implement immediate mitigations including patching affected Silverlight runtime versions to 5.1.20125.0 or later, which contains the necessary pointer validation fixes. Organizations should also consider implementing network-level controls such as web application firewalls and content filtering to restrict access to potentially malicious Silverlight content. Additionally, security monitoring should be enhanced to detect unusual memory access patterns or suspicious Silverlight application behavior. The remediation strategy should also include comprehensive vulnerability assessments to identify all systems running affected Silverlight versions and ensure proper patch management protocols are in place to prevent future exposure to similar vulnerabilities. This vulnerability demonstrates the importance of proper memory management practices and the critical need for robust pointer validation in runtime environments that handle untrusted content.