CVE-2015-0020 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6 through 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-2015-0017, CVE-2015-0022, CVE-2015-0026, CVE-2015-0030, CVE-2015-0031, CVE-2015-0036, and CVE-2015-0041.
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Analysis
by VulDB Data Team • 03/09/2022
The vulnerability identified as CVE-2015-0020 represents a critical memory corruption flaw affecting Microsoft Internet Explorer versions 6 through 11. This vulnerability falls under the broader category of remote code execution exploits that have historically plagued web browsers, making it particularly dangerous in enterprise and consumer environments where IE remains widely deployed. The flaw enables attackers to craft malicious websites that can trigger arbitrary code execution or cause denial of service conditions when users browse to these compromised sites. The vulnerability operates by exploiting memory handling mechanisms within the browser's rendering engine, specifically targeting how Internet Explorer processes certain web content structures that lead to memory corruption states. This type of vulnerability is classified as a memory safety issue and aligns with common weakness enumerations such as CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations.
The technical exploitation of CVE-2015-0020 occurs through carefully constructed web content that manipulates the browser's memory management systems to overwrite critical memory locations or execute unintended code sequences. Attackers typically leverage this vulnerability by hosting malicious web pages that contain specially crafted JavaScript or ActiveX controls designed to trigger the memory corruption. The exploit chain often begins with a user visiting a compromised website, followed by the browser's processing of malformed content that leads to memory corruption. This vulnerability demonstrates the complexity of modern browser security models where the interaction between multiple subsystems creates numerous potential attack surfaces. The exploit techniques associated with this vulnerability often involve heap spraying methods and use of specific memory layout characteristics to achieve reliable code execution, making it particularly challenging to defend against without proper patching.
The operational impact of CVE-2015-0020 extends beyond simple denial of service conditions to include complete system compromise when successful. Organizations running affected Internet Explorer versions face significant risk of data breaches, malware installation, and persistent backdoor access when users visit malicious websites. The vulnerability's presence in multiple IE versions from version 6 through 11 creates a broad attack surface that spans nearly two decades of browser releases, making it particularly concerning for legacy environments and organizations unable to immediately migrate to newer browser versions. Security professionals must consider the vulnerability's potential for use in targeted attacks, spear-phishing campaigns, and advanced persistent threat operations. The impact is further amplified by the fact that many enterprise environments continue to support older IE versions for compatibility reasons, creating extended windows of exposure. This vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the T1059.007 technique for command and scripting interpreter and T1203 for exploitation for privilege escalation.
Mitigation strategies for CVE-2015-0020 primarily focus on immediate patching and implementation of defensive measures. Microsoft released security updates that addressed this vulnerability through the regular security bulletin process, making timely patch deployment the primary defense mechanism. Organizations should implement browser hardening techniques including disabling unnecessary features, restricting ActiveX controls, and implementing content security policies to limit the impact of such exploits. Network-level defenses such as web application firewalls and intrusion prevention systems can help detect and block known exploit patterns associated with this vulnerability. Security teams should also consider implementing browser isolation techniques and sandboxing mechanisms to contain potential exploitation attempts. The vulnerability's classification as a memory corruption issue makes it particularly susceptible to exploit mitigation techniques such as address space layout randomization and data execution prevention, though these measures are most effective when combined with proper patch management. Regular vulnerability assessments and penetration testing should include evaluation of IE installations to identify systems running affected versions and ensure proper remediation measures are in place.