CVE-2015-6085 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 10 and 11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Internet Explorer Memory Corruption Vulnerability," a different vulnerability than CVE-2015-6064 and CVE-2015-6084.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 11/28/2024
This vulnerability represents a critical memory corruption flaw in Microsoft Internet Explorer versions 10 and 11 that enables remote code execution through maliciously crafted web content. The vulnerability stems from improper handling of memory operations within the browser's rendering engine, specifically affecting how Internet Explorer processes certain web elements and JavaScript objects. Attackers can leverage this weakness by hosting malicious websites that trigger memory corruption when the browser attempts to render or execute specific content patterns. The flaw operates at a fundamental level within the browser's memory management system, creating opportunities for attackers to overwrite critical memory locations and potentially execute arbitrary code with the privileges of the logged-in user. This vulnerability is distinct from related issues CVE-2015-6064 and CVE-2015-6084, indicating separate code paths and exploitation mechanisms that require different defensive approaches. The memory corruption occurs during normal browsing operations when the browser encounters specially crafted HTML elements, JavaScript code, or ActiveX controls that cause the memory allocator to behave unexpectedly. The impact extends beyond simple code execution to include potential denial of service conditions where the browser process crashes or becomes unstable, disrupting user productivity and potentially providing attackers with additional attack vectors.
The technical implementation of this vulnerability involves exploitation of memory management weaknesses in Internet Explorer's JavaScript engine and rendering components. When a user visits a malicious website, the browser's memory allocator encounters malformed or unexpected data structures that cause it to write beyond allocated memory boundaries or corrupt heap metadata. This type of vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions. Attackers typically craft web pages containing malicious JavaScript code that triggers specific memory allocation patterns, often involving object manipulation, array operations, or memory fragmentation attacks. The exploitation process may involve information disclosure attacks, where attackers first gather information about memory layout before executing precise memory corruption attacks. The vulnerability affects the browser's ability to properly manage memory resources during web page rendering, particularly when handling complex JavaScript objects and DOM manipulations. The attack surface includes various web technologies such as HTML, CSS, JavaScript, and ActiveX controls that can be manipulated to trigger the memory corruption conditions. This vulnerability is particularly dangerous because it can be exploited through social engineering techniques, where users are tricked into visiting malicious websites through phishing emails, compromised websites, or malicious advertisements.
The operational impact of this vulnerability extends far beyond individual user compromise to affect enterprise environments and organizational security postures. Organizations running Internet Explorer 10 and 11 are exposed to potential full system compromise when users visit malicious websites, as the vulnerability allows attackers to execute code with the user's privileges and potentially escalate to SYSTEM level access. The vulnerability affects both desktop and mobile versions of Internet Explorer, though the mobile variants may have different exploitation characteristics. Security teams must consider the broader implications of this vulnerability, including potential lateral movement within networks if attackers gain initial access through this vector. The vulnerability's impact is amplified by the widespread adoption of Internet Explorer in enterprise environments, where many organizations still rely on legacy browser versions for compatibility reasons. Organizations may experience service disruption due to browser crashes, rendering systems unusable until patches are deployed. The vulnerability also affects organizations that depend on Internet Explorer for business-critical applications, potentially causing operational downtime and productivity losses. Incident response teams must prepare for potential exploitation attempts, as the vulnerability can be used in targeted attacks against specific organizations or industries. The attack vector is particularly concerning because it can be delivered through various means including email attachments, web-based attacks, and compromised websites, making traditional network-based defenses insufficient for protection.
Mitigation strategies for this vulnerability require a multi-layered approach combining immediate patch management with defensive measures. Microsoft released security updates addressing this vulnerability through regular security patches, which should be deployed immediately across all affected systems. Organizations should implement browser hardening techniques including disabling unnecessary features, restricting ActiveX controls, and implementing content security policies to limit potential exploitation vectors. Network-based defenses such as web application firewalls and intrusion prevention systems can help detect and block malicious traffic patterns associated with exploitation attempts. Browser sandboxing techniques and privilege separation mechanisms can limit the damage if exploitation occurs, preventing attackers from gaining full system access. Security awareness training for users remains critical, as many exploitation attempts rely on social engineering to deliver malicious payloads to unsuspecting users. Regular vulnerability assessments should include checks for unpatched Internet Explorer installations and monitoring for suspicious web traffic patterns. Organizations should consider implementing browser migration strategies to transition away from Internet Explorer to more modern, secure browsers that have better security track records. The vulnerability highlights the importance of maintaining up-to-date security patches and implementing comprehensive security monitoring to detect exploitation attempts before they succeed. Continuous monitoring and threat intelligence feeds should be utilized to identify new attack patterns and emerging threats targeting this vulnerability. Additionally, organizations should consider implementing automated patch management systems to ensure rapid deployment of security updates across all endpoints. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for Windows Command Shell and T1059.001 for Command and Scripting Interpreter, indicating that exploitation often involves command execution techniques that leverage the compromised browser environment.