CVE-2008-4071 in Acrobat
Summary
by MITRE
A certain ActiveX control in Adobe Acrobat 9, when used with Microsoft Windows Vista and Internet Explorer 7, allows remote attackers to cause a denial of service (browser crash) via an src property value with an invalid acroie:// URL.
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Analysis
by VulDB Data Team • 11/03/2024
The vulnerability described in CVE-2008-4071 represents a critical denial of service flaw within Adobe Acrobat 9's ActiveX control implementation on Windows Vista systems running Internet Explorer 7. This issue specifically targets the interaction between Adobe's proprietary ActiveX component and Microsoft's web browser, creating a pathway for remote attackers to disrupt normal system operations. The vulnerability manifests when the ActiveX control processes an src property value containing an invalid acroie:// URL, leading to browser instability and potential system crashes. This particular combination of software components creates a unique attack surface that exploits the trust relationship between Internet Explorer and ActiveX controls, allowing malicious actors to leverage the browser's handling of malformed URLs to trigger system failures.
The technical root cause of this vulnerability lies in insufficient input validation within Adobe Acrobat 9's ActiveX control implementation. When Internet Explorer encounters an HTML element referencing the Acrobat ActiveX control with an invalid acroie:// URL in the src attribute, the control fails to properly sanitize or validate the input before processing it. This lack of proper validation creates a condition where malformed URL schemes can cause memory corruption or stack overflow conditions within the ActiveX control's execution environment. The vulnerability specifically affects the Windows Vista operating system due to its security model and memory management characteristics, combined with Internet Explorer 7's handling of ActiveX controls. The acroie:// protocol scheme, which is designed to facilitate communication between Internet Explorer and Acrobat's ActiveX control, becomes exploitable when improperly formatted URLs are processed, leading to the browser crashing or becoming unresponsive.
The operational impact of CVE-2008-4071 extends beyond simple browser disruption, as it can be leveraged to create persistent denial of service conditions that affect user productivity and system availability. Attackers can craft malicious web pages that, when loaded in Internet Explorer on vulnerable systems, will automatically trigger the ActiveX control with the malformed URL, causing immediate browser crashes. This vulnerability is particularly concerning in enterprise environments where users may inadvertently browse to compromised websites or receive malicious emails with embedded links. The exploit requires no special privileges or user interaction beyond visiting a malicious website, making it a significant threat vector for targeted attacks. The vulnerability's impact is amplified by the fact that Adobe Acrobat 9 was widely deployed in corporate environments, making many systems potentially vulnerable to this type of attack.
Mitigation strategies for CVE-2008-4071 should focus on both immediate defensive measures and long-term remediation approaches. Organizations should implement browser security policies that restrict ActiveX control usage or disable ActiveX controls entirely when not required for legitimate business functions. The most effective immediate solution involves updating to a patched version of Adobe Acrobat 9 that properly validates URL inputs and handles malformed acroie:// schemes. System administrators should also consider implementing web application firewalls or content filtering solutions that can detect and block malicious URL patterns targeting ActiveX controls. From a defensive standpoint, the vulnerability aligns with CWE-170, which addresses improper input handling, and can be mapped to ATT&CK technique T1211 for exploitation of software vulnerabilities. Regular patch management processes should be enhanced to ensure rapid deployment of security updates for Adobe products, particularly given the widespread use of Acrobat across enterprise environments. Additionally, user education regarding suspicious website visits and email attachments remains crucial in preventing exploitation of this vulnerability through social engineering vectors.