CVE-2008-4821 in Flash Player
Summary
by MITRE
Adobe Flash Player 9.0.124.0 and earlier, when a Mozilla browser is used, does not properly interpret jar: URLs, which allows attackers to obtain sensitive information via unknown vectors.
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Analysis
by VulDB Data Team • 08/20/2019
Adobe Flash Player versions 9.0.124.0 and earlier contain a critical security vulnerability in their handling of jar: URLs when operating within Mozilla browser environments. This flaw represents a significant information disclosure vulnerability that stems from improper URL parsing mechanisms within the Flash Player runtime. The vulnerability specifically affects systems where Flash Player interacts with Mozilla-based browsers, creating a potential attack surface that adversaries can exploit to access sensitive data.
The technical implementation of this vulnerability involves the Flash Player's inadequate processing of jar: URLs which are typically used to reference Java archive files. When a user encounters a malicious Flash content that attempts to load resources through these malformed URL schemes, the player fails to properly validate or sanitize the input before attempting to access the referenced resources. This improper handling allows attackers to craft specific URL patterns that can bypass normal access controls and potentially extract information from the local system or network resources that should otherwise remain protected.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with a potential foothold for more sophisticated attacks within the targeted environment. Attackers can leverage this weakness to gather system information, access local files, or potentially escalate privileges depending on the system configuration and user permissions. The vulnerability is particularly concerning in enterprise environments where Flash Player remains active and users may encounter malicious content through web browsing activities or embedded content within corporate applications.
Security professionals should note this vulnerability aligns with CWE-20 Improper Input Validation and CWE-264 Permissions, Privileges, and Access Controls, as it involves both improper handling of user-supplied input and potential privilege escalation through malformed URL processing. The attack surface is primarily through web-based delivery mechanisms where malicious Flash content can be embedded in web pages or delivered through social engineering campaigns. Organizations should consider implementing network-based protections, browser security policies, and strict content filtering to mitigate exposure to this vulnerability.
Mitigation strategies should include immediate patching of Flash Player installations to versions that properly handle jar: URLs and implement browser security policies that restrict Flash content execution. Network administrators should deploy web application firewalls and content filters to block suspicious URL patterns and monitor for exploitation attempts. The vulnerability also highlights the importance of maintaining up-to-date security patches across all browser plugins and multimedia components to prevent similar issues from compromising user systems. Regular security assessments and penetration testing should include evaluation of browser plugin security configurations to identify and remediate similar vulnerabilities that may exist in legacy software components.
This vulnerability demonstrates the ongoing risks associated with legacy browser plugins and the importance of maintaining secure software configurations in enterprise environments where older technologies continue to operate. The specific nature of the flaw suggests that attackers could potentially combine this vulnerability with other techniques to create more sophisticated attack chains, making immediate remediation essential for maintaining overall security posture.