CVE-2016-3267 in Edge
Summary
by MITRE
Microsoft Internet Explorer 9 through 11 and Microsoft Edge allow remote attackers to determine the existence of unspecified files via a crafted web site, aka "Microsoft Browser Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 09/23/2022
This vulnerability represents a significant information disclosure flaw in Microsoft web browsers that affects Internet Explorer versions 9 through 11 and Microsoft Edge. The vulnerability stems from how these browsers handle file existence checks through crafted web content, allowing remote attackers to infer the presence or absence of specific files on a target system. The flaw operates at the browser level where malicious websites can exploit the rendering engine's behavior to perform indirect file enumeration attacks, potentially revealing sensitive information about the underlying operating system's file structure.
The technical mechanism behind this vulnerability involves the exploitation of browser rendering behaviors and JavaScript APIs that interact with local file system operations. Attackers can craft web pages that attempt to access or reference files in ways that cause the browser to behave differently based on whether those files exist on the target system. This differential behavior creates observable side effects that can be measured and analyzed to determine file existence. The vulnerability is classified under CWE-200 as an information disclosure weakness, specifically related to the exposure of file system information through improper access controls and inadequate validation of file access attempts.
From an operational perspective, this vulnerability poses a serious threat to enterprise security environments where attackers could use it to map out file systems and identify potentially sensitive files such as configuration files, database files, or system binaries. The impact extends beyond simple reconnaissance as it can provide attackers with intelligence for subsequent exploitation attempts, including identifying vulnerable software versions or locating files that might contain credentials or other sensitive data. The vulnerability's remote nature means that attackers do not require physical access to target systems and can exploit it through standard web browsing activities, making it particularly dangerous in corporate environments where users frequently browse the internet.
The attack surface for this vulnerability encompasses any user who visits a malicious website while using affected browser versions, creating a broad potential impact across different user groups and organizational sizes. Security professionals should note that this vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1056.001 (Input Capture) as it enables attackers to gather information about system files and potentially use this information for more sophisticated attacks. Organizations should implement layered mitigations including browser updates, network-based filtering to block suspicious content, and user education about avoiding untrusted websites. Additionally, security teams should monitor for indicators of compromise related to file enumeration activities and ensure that browser security settings are properly configured to limit file system access through web content.