CVE-2012-1873 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 7 through 9 does not properly create and initialize string data, which allows remote attackers to obtain sensitive information from process memory via a crafted HTML document, aka "Null Byte Information Disclosure Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/25/2021
The vulnerability identified as CVE-2012-1873 represents a critical information disclosure flaw affecting Microsoft Internet Explorer versions 7 through 9. This vulnerability stems from improper handling of string data initialization within the browser's rendering engine, specifically impacting how null byte sequences are processed during HTML document parsing. The flaw enables malicious actors to craft specially designed HTML documents that can trigger memory corruption behaviors, potentially exposing sensitive data from the browser process memory space. This issue falls under the broader category of memory safety vulnerabilities and aligns with CWE-125, which addresses out-of-bounds read conditions that can lead to information disclosure.
The technical exploitation of this vulnerability occurs when Internet Explorer encounters malformed string data structures during document parsing operations. When processing crafted HTML content containing specific null byte sequences, the browser fails to properly initialize string variables, leading to uninitialized memory being exposed to attackers. This memory exposure can contain sensitive information such as stack contents, heap data, or other process-specific information that may reveal system state, application data, or even credentials. The vulnerability operates at the application layer and requires user interaction through visiting malicious web pages or opening compromised email attachments containing the malicious HTML content.
The operational impact of CVE-2012-1873 extends beyond simple information disclosure, as the leaked memory contents could potentially contain cryptographic keys, session tokens, or other sensitive data that could be leveraged for further attacks. Attackers could use this information to perform credential harvesting, session hijacking, or to gain insights into the target system's memory layout for more sophisticated exploitation techniques. The vulnerability affects a wide range of Windows operating systems that include the affected Internet Explorer versions, making it particularly dangerous in enterprise environments where legacy browser support remains common. This type of vulnerability is categorized under the ATT&CK framework as part of the T1059.001 technique for command and scripting interpreter, though it primarily functions as an information gathering primitive that enables subsequent attack vectors.
Mitigation strategies for this vulnerability include immediate deployment of Microsoft security patches and updates that address the string initialization flaw in Internet Explorer. Organizations should implement browser hardening measures such as disabling unnecessary browser features, implementing content security policies, and utilizing sandboxing technologies to limit the impact of potential exploitation. Additionally, network-based defenses including web application firewalls and intrusion detection systems can help detect and block malicious HTML content targeting this vulnerability. Regular security assessments and vulnerability scanning should include checks for outdated browser versions that may still be vulnerable to this and similar memory corruption issues. The remediation process should also involve user education to prevent accidental interaction with malicious web content, as successful exploitation typically requires user engagement with crafted web pages.