CVE-2015-2412 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 10 and 11 allows remote attackers to read arbitrary local files via a crafted pathname, aka "Internet Explorer Information Disclosure Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 11/29/2024
Microsoft Internet Explorer 10 and 11 contained a critical information disclosure vulnerability that enabled remote attackers to access arbitrary local files on affected systems through carefully crafted pathname inputs. This vulnerability falls under the category of improper input validation and path traversal flaws, specifically representing a variant of the common directory traversal attack vector. The flaw existed in how the browser handled file path resolution when processing certain URL schemes and local file references, allowing malicious actors to bypass normal file access restrictions and retrieve sensitive data from the local file system.
The technical implementation of this vulnerability stemmed from inadequate sanitization of user-supplied input within the browser's file handling mechanisms. When Internet Explorer encountered specially crafted URLs containing malformed path sequences, the browser would incorrectly process these inputs and resolve them to local file system locations without proper access controls. This occurred particularly when processing file:/// URLs or other local resource references where the application failed to properly validate or normalize the provided path information. Attackers could exploit this by constructing malicious URLs that would traverse directory structures and access files that should normally be restricted, including system configuration files, user documents, or application data.
The operational impact of this vulnerability was significant as it provided attackers with unauthorized access to potentially sensitive local information. Depending on the system configuration and user permissions, successful exploitation could lead to the disclosure of personal documents, system configuration files, application data, or even credentials stored in local files. The vulnerability was particularly dangerous because it could be exploited through web-based attacks without requiring any special privileges or local system access. This made it a prime target for phishing campaigns or drive-by download attacks where users would inadvertently trigger the vulnerability simply by visiting a malicious website.
From a cybersecurity perspective, this vulnerability aligns with CWE-22 which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The flaw also maps to several ATT&CK techniques including T1059 for command and scripting interpreter and T1566 for spearphishing with a malicious attachment, as attackers could use this vulnerability to access and exfiltrate sensitive data. The vulnerability's exploitation typically required a user to visit a malicious website, making it particularly dangerous in enterprise environments where users might encounter such sites through social engineering or compromised web applications.
Organizations should have implemented immediate mitigations including applying the relevant Microsoft security updates, configuring browser security settings to restrict local file access, and implementing network monitoring to detect suspicious file access patterns. Additional defensive measures included deploying web application firewalls to filter malicious path sequences, implementing strict access controls for local file system resources, and conducting user awareness training to recognize potentially malicious web content. The vulnerability highlighted the importance of proper input validation and the need for comprehensive security testing of web browser components, particularly those handling local file system operations. Organizations should have also reviewed their incident response procedures to ensure rapid detection and remediation of similar vulnerabilities in their browser environments.