CVE-2018-6084 in Chrome
Summary
by MITRE
Insufficiently sanitized distributed objects in Updater in Google Chrome on macOS prior to 66.0.3359.117 allowed a local attacker to execute arbitrary code via an executable file.
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Analysis
by VulDB Data Team • 07/20/2024
The vulnerability identified as CVE-2018-6084 represents a critical security flaw in Google Chrome's updater component on macOS systems. This issue stems from inadequate sanitization of distributed objects within the updater mechanism, creating a pathway for local attackers to escalate privileges and execute malicious code. The vulnerability specifically affects Chrome versions prior to 66.0.3359.117, making a significant portion of users susceptible to exploitation. The flaw resides in how the updater processes distributed objects, which are typically used for inter-process communication and object serialization in macOS environments. When these objects are not properly sanitized, they can contain malicious payloads that are executed with the privileges of the updater process, potentially leading to full system compromise.
The technical exploitation of this vulnerability involves a local attacker crafting a specially prepared executable file that, when processed by the vulnerable Chrome updater, triggers arbitrary code execution. This represents a privilege escalation vector where the attacker leverages the updater's elevated permissions to execute malicious code. The distributed objects in question are likely processed through Objective-C or Swift frameworks that handle inter-application communication, and the insufficient sanitization means that untrusted input can be interpreted as executable instructions. The vulnerability aligns with CWE-123, which addresses "Uncontrolled Format String," and CWE-78, "Improper Neutralization of Special Elements used in OS Command Injection," though the specific implementation focuses more on object deserialization and process interaction. From an attack perspective, this vulnerability maps to the ATT&CK technique T1059.001 for command and script injection, and T1068 for exploit for privilege escalation, as the attacker can leverage the updater's elevated privileges to gain broader system access.
The operational impact of CVE-2018-6084 extends beyond simple code execution, as it provides a persistent foothold for attackers to establish long-term system compromise. Once an attacker successfully exploits this vulnerability, they can potentially install additional malware, modify system files, or establish backdoors that persist across reboots. The local nature of the attack means that physical access to the system or an existing low-privilege foothold is sufficient to trigger the exploit, making it particularly dangerous in environments where users may have access to the target system. Organizations running affected Chrome versions face significant risk, as this vulnerability could be exploited by malicious insiders or attackers who have already gained access to a user account. The exploit chain typically involves the attacker placing a malicious executable in a location where the updater will process it, often through social engineering or by leveraging other initial access vectors. The vulnerability's impact is compounded by Chrome's widespread usage and the updater's privileged execution context, which provides attackers with elevated system capabilities. Security teams should prioritize patching affected systems, as the exploitation of this vulnerability can lead to complete system compromise and data exfiltration.
Mitigation strategies for CVE-2018-6084 focus primarily on immediate remediation through software updates. Organizations must ensure all affected Chrome installations are updated to version 66.0.3359.117 or later, which contains the necessary patches to address the insufficient sanitization of distributed objects. Additional defensive measures include implementing application whitelisting policies to restrict execution of unauthorized binaries, monitoring for unusual updater activity, and maintaining comprehensive system monitoring to detect potential exploitation attempts. Network segmentation and privilege separation can help limit the damage if exploitation occurs, while regular security audits should verify that no unauthorized modifications have occurred. The vulnerability highlights the importance of secure coding practices in inter-process communication mechanisms and underscores the need for thorough input validation and sanitization in all distributed object processing. Security teams should also consider implementing automated patch management systems to ensure timely deployment of security updates across all affected systems. Regular vulnerability assessments and penetration testing can help identify similar weaknesses in other software components, while employee security awareness training should cover the risks associated with executing unknown or untrusted executables. The remediation process should include verification that the update was successfully applied and that no malicious code remains in the system, as the vulnerability's exploitation could potentially leave persistent backdoors or modified system components.