CVE-2017-5124 in Chrome
Summary
by MITRE
Incorrect application of sandboxing in Blink in Google Chrome prior to 62.0.3202.62 allowed a remote attacker to inject arbitrary scripts or HTML (UXSS) via a crafted MHTML page.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/22/2025
The vulnerability identified as CVE-2017-5124 represents a critical sandboxing bypass in Google Chrome's Blink rendering engine that existed prior to version 62.0.3202.62. This flaw specifically targeted the MHTML (MIME HTML) handling mechanism within the browser's security architecture, creating a pathway for remote code execution through cross-site scripting attacks. The vulnerability stems from an improper implementation of sandboxing controls that should have prevented malicious content from executing outside its designated boundaries. MHTML pages, which are designed to encapsulate HTML content along with embedded resources in a single file format, were exploited to circumvent Chrome's security model that typically isolates web content from the underlying system.
The technical exploitation of this vulnerability relies on the browser's failure to properly validate and isolate MHTML content within its sandboxed environment. When Chrome processes a crafted MHTML page, the vulnerability allows an attacker to inject arbitrary scripts or HTML content that bypasses the intended security boundaries. This occurs because the sandboxing mechanism does not adequately distinguish between legitimate embedded content and malicious payloads within the MHTML structure. The flaw operates at the intersection of content parsing and security boundary enforcement, where the browser's handling of MIME-type content fails to maintain proper isolation between different execution contexts.
From an operational perspective, this vulnerability poses significant risk to users of affected Chrome versions as it enables remote attackers to execute arbitrary code on target systems without requiring user interaction beyond visiting a malicious website. The exploitation chain typically involves hosting a specially crafted MHTML file on a web server that, when accessed through the vulnerable browser, triggers the sandbox escape mechanism. This allows attackers to execute malicious scripts with the privileges of the browser process, potentially leading to full system compromise. The vulnerability's impact extends beyond simple XSS attacks as it enables more sophisticated attack vectors including credential theft, data exfiltration, and system control.
The security implications of CVE-2017-5124 align with CWE-117, which describes improper output neutralization for logs, and ATT&CK technique T1059.007 for command and scripting interpreter. The vulnerability demonstrates a classic sandboxing bypass where the security controls designed to isolate potentially malicious content are circumvented through improper validation of content types. Organizations should implement immediate mitigation strategies including prompt browser updates to version 62.0.3202.62 or later, network-level filtering of suspicious MHTML content, and enhanced monitoring for unusual browser behavior. Additionally, security teams should consider implementing web application firewalls and content security policies that restrict MHTML content handling to reduce the attack surface. The vulnerability underscores the critical importance of maintaining up-to-date security patches and demonstrates how even minor implementation flaws in core browser components can create significant security risks for end users.