CVE-2016-3391 in Edge
Summary
by MITRE
Microsoft Internet Explorer 10 and 11 and Microsoft Edge allow context-dependent attackers to discover credentials by leveraging access to a memory dump, aka "Microsoft Browser Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 09/23/2022
The vulnerability identified as CVE-2016-3391 represents a critical information disclosure flaw affecting Microsoft Internet Explorer versions 10 and 11, as well as Microsoft Edge browser implementations. This vulnerability stems from insufficient memory management practices that allow attackers with access to memory dump files to extract sensitive credential information from the browser processes. The flaw operates through a memory corruption mechanism that exposes authentication tokens and session data in a manner consistent with information disclosure vulnerabilities classified under CWE-200. Attackers can leverage this weakness by obtaining memory dumps from compromised systems and then analyzing these dumps to recover stored credentials, potentially including usernames, passwords, and authentication tokens that were previously cached by the affected browsers.
The technical execution of this vulnerability relies on the browser's handling of memory segments containing credential information, particularly when the browser processes are running in memory. When Internet Explorer or Edge encounters certain memory operations, particularly during authentication flows or when processing web content, they may leave credential data in memory locations that are not properly cleared or secured. This creates an attack surface where an adversary with access to memory dump files can perform forensic analysis to extract sensitive information that was previously processed by the browser. The vulnerability specifically exploits the memory management practices of these browsers, where credential data is not adequately sanitized from memory after use, creating persistent exposure windows that persist even after the browser session ends. The attack vector requires local access to memory dumps, making it a context-dependent vulnerability that typically occurs in scenarios involving system compromise or insider threats.
The operational impact of this vulnerability extends beyond simple credential theft, as it can enable attackers to maintain persistent access to compromised systems and escalate privileges within network environments. When attackers successfully extract credentials from memory dumps, they can use this information to authenticate to various services, potentially gaining access to corporate networks, cloud resources, and sensitive databases. The vulnerability particularly affects organizations where browsers are used to access internal systems, as the extracted credentials may include domain authentication tokens, single sign-on information, or service account credentials. This creates a significant risk for enterprises where browser-based applications are prevalent, as the compromise of a single user session could potentially provide access to multiple systems if the same credentials are reused across different services. The vulnerability also impacts user privacy and data protection compliance, as it could result in unauthorized disclosure of personal authentication information.
Mitigation strategies for CVE-2016-3391 should focus on both immediate remediation and long-term security improvements in browser memory management practices. Microsoft addressed this vulnerability through security updates that improved memory sanitization processes and reduced the persistence of credential information in memory. Organizations should implement comprehensive patch management procedures to ensure all affected browser versions are updated promptly. Additional mitigations include implementing memory protection mechanisms such as address space layout randomization and data execution prevention, which can make memory dump analysis more difficult for attackers. Security professionals should also consider implementing network monitoring to detect unusual memory dump creation activities and establish strict access controls on systems where browsers are used for sensitive operations. The vulnerability aligns with ATT&CK technique T1003.001 which covers credential dumping, and organizations should incorporate this into their threat hunting and incident response procedures to detect potential exploitation attempts. Regular security assessments should include memory analysis capabilities to identify potential exposure windows and ensure proper credential handling practices are maintained across browser implementations.