CVE-2017-5078 in Chrome
Summary
by MITRE
Insufficient validation of untrusted input in Blink's mailto: handling in Google Chrome prior to 59.0.3071.86 for Linux, Windows, and Mac allowed a remote attacker to perform command injection via a crafted HTML page, a similar issue to CVE-2004-0121. For example, characters such as * have an incorrect interaction with xdg-email in xdg-utils, and a space character can be used in front of a command-line argument.
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Analysis
by VulDB Data Team • 01/04/2023
The vulnerability identified as CVE-2017-5078 represents a critical command injection flaw within Google Chrome's Blink rendering engine that affected versions prior to 59.0.3071.86 across Linux, Windows, and Mac platforms. This security weakness stems from inadequate validation of untrusted input when processing mailto: URLs, creating a pathway for remote attackers to execute arbitrary commands on affected systems. The flaw specifically manifests in how Chrome handles email links that contain specially crafted payloads, allowing malicious actors to exploit the underlying system command execution mechanisms.
The technical exploitation of this vulnerability leverages the interaction between Chrome's mailto: handler and system utilities like xdg-email in Linux environments. When a user clicks on a malicious mailto: link, the browser passes the email address parameter to the system's default email client handler without proper sanitization. Characters such as asterisks and spaces can be manipulated to inject additional command-line arguments, effectively bypassing input validation mechanisms. This behavior mirrors the patterns seen in CVE-2004-0121, establishing a precedent for similar command injection vulnerabilities in email handling systems. The vulnerability operates at the intersection of web browser security and operating system command execution, where the browser's insufficient input validation creates an attack surface that can be leveraged for privilege escalation.
The operational impact of CVE-2017-5078 extends beyond simple command execution, as it can enable attackers to perform a wide range of malicious activities including unauthorized data access, system compromise, and persistence mechanisms. Remote attackers can craft HTML pages that, when visited by victims, automatically trigger command injection payloads without requiring user interaction beyond clicking a link. This makes the vulnerability particularly dangerous in phishing campaigns or when exploited through compromised websites. The attack vector is especially concerning because it can be delivered through standard web browsing activities, making it difficult for users to distinguish between legitimate and malicious content. The vulnerability affects all operating systems where Chrome is installed, creating a broad attack surface that spans multiple platforms.
Mitigation strategies for CVE-2017-5078 primarily involve updating to Chrome version 59.0.3071.86 or later, which includes proper input validation and sanitization for mailto: URL handling. Organizations should implement comprehensive patch management procedures to ensure all systems are updated promptly, as this vulnerability can be exploited remotely without user interaction. Additionally, network administrators can consider implementing web application firewalls that monitor for suspicious mailto: URL patterns and can block potentially malicious content. The vulnerability aligns with CWE-74 standards for Improper Neutralization of Special Elements in Output Used by a Downstream Component, and its exploitation patterns correspond to ATT&CK technique T1059.007 for Command and Scripting Interpreter. Security teams should also consider implementing browser hardening measures such as disabling automatic mailto: link handling or configuring browsers to require explicit user confirmation before executing system commands. Organizations may want to monitor for exploitation attempts through network traffic analysis, looking for unusual patterns in mailto: URL parameters that could indicate attempted command injection attacks.