CVE-2017-15404 in Chrome
Summary
by MITRE
An ability to process crash dumps under root privileges and inappropriate symlinks handling could lead to a local privilege escalation in Crash Reporting in Google Chrome on Chrome OS prior to 61.0.3163.113 allowed a local attacker to perform privilege escalation via a crafted HTML page.
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Analysis
by VulDB Data Team • 04/26/2020
The vulnerability identified as CVE-2017-15404 represents a critical local privilege escalation flaw within Google Chrome's crash reporting mechanism on Chrome OS systems. This vulnerability specifically affects versions prior to 61.0.3163.113 and stems from improper handling of symbolic links during crash dump processing operations that occur with root privileges. The flaw exists in the way Chrome OS manages crash reporting processes, creating an opportunity for malicious actors to exploit the system through carefully crafted HTML content.
The technical execution of this vulnerability relies on the improper management of symbolic link resolution within the crash reporting framework. When Chrome processes crash dumps under root privileges, it fails to properly validate or sanitize symbolic link paths, allowing an attacker to manipulate file system references. This misconfiguration enables a local attacker to create malicious symbolic links that point to sensitive system files or directories, which are then accessed during the crash reporting process. The vulnerability falls under CWE-367, which specifically addresses Time-of-Check to Time-of-Use (TOCTOU) race conditions, where the system's behavior changes between the time a check is performed and when the action is executed.
The operational impact of this vulnerability is severe as it allows a local attacker with minimal privileges to escalate their access level to root, effectively compromising the entire system. The attack vector requires only a crafted HTML page that can be delivered through web-based means, making it particularly dangerous in environments where users might encounter malicious content. Once successfully exploited, the attacker gains complete control over the Chrome OS device, potentially enabling further lateral movement within a network or access to sensitive data stored on the system. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1068, which covers 'Local Privilege Escalation', and T1190, which covers 'Exploit Public-Facing Application'.
Mitigation strategies for CVE-2017-15404 primarily involve updating Chrome OS to version 61.0.3163.113 or later, which includes patches that properly handle symbolic link resolution during crash reporting processes. Organizations should also implement additional security measures such as restricting user privileges, monitoring for suspicious crash reporting activities, and ensuring proper file system permissions are maintained. The fix addresses the core issue by implementing proper validation of symbolic link targets and ensuring that crash reporting operations do not proceed with potentially compromised file references. Security teams should also consider deploying network monitoring solutions to detect unusual crash reporting patterns that might indicate exploitation attempts, while maintaining comprehensive logging of system activities related to privilege escalation mechanisms.