CVE-2023-4357 in Chrome
Summary
by MITRE • 08/15/2023
Insufficient validation of untrusted input in XML in Google Chrome prior to 116.0.5845.96 allowed a remote attacker to bypass file access restrictions via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/01/2024
This vulnerability represents a critical flaw in Google Chrome's XML processing mechanism that emerged prior to version 116.0.5845.96. The issue stems from inadequate validation of untrusted input within XML parsers, creating a pathway for remote attackers to circumvent file access restrictions that are typically enforced by web browsers. The vulnerability specifically affects Chrome's handling of XML data structures when processed through HTML pages, allowing malicious actors to exploit the insufficient input validation to access files that should remain restricted. This type of vulnerability falls under the category of input validation flaws that can lead to privilege escalation and unauthorized data access. The Chromium security severity rating of Medium indicates the potential for significant impact, particularly when considering how XML processing is commonly used in web applications and how file access restrictions are fundamental to browser security models. This vulnerability is particularly concerning because it operates at the intersection of XML processing and file system access controls, creating a potential attack vector that could allow remote code execution or data exfiltration.
The technical implementation of this vulnerability involves Chrome's XML parser failing to properly validate or sanitize untrusted input that originates from HTML pages containing crafted XML content. When a malicious HTML page loads XML data that has been carefully constructed to exploit this validation gap, the browser's XML processing engine does not adequately verify the integrity or legitimacy of the input before proceeding with file access operations. This flaw enables attackers to manipulate XML parsing behavior in ways that should normally be prevented by browser security policies. The vulnerability demonstrates a classic example of insufficient input validation, where the system fails to properly validate or sanitize data before processing it, allowing malicious input to bypass security checks that are intended to protect against unauthorized file access. The attack surface is expanded through the use of HTML pages that contain embedded XML, which is a common pattern in web applications that utilize XML for data exchange or configuration purposes. This particular vulnerability is classified under CWE-20, which specifically addresses "Improper Input Validation," and aligns with attack patterns found in the ATT&CK framework under techniques related to privilege escalation and data access.
The operational impact of this vulnerability extends beyond simple file access bypasses and can potentially enable more sophisticated attacks depending on the environment and system configuration. Remote attackers could leverage this vulnerability to access sensitive files on the target system, including configuration files, user data, or system resources that should remain protected. The medium severity rating indicates that while the vulnerability may not be immediately exploitable in all scenarios, it presents a significant risk when combined with other attack vectors or when targeting specific system configurations. The attack requires a remote HTML page to be loaded in Chrome, which means that users could be tricked into visiting malicious websites or clicking on phishing links. The vulnerability is particularly dangerous in enterprise environments where users may have access to sensitive data or where the browser is used to access internal systems. Organizations may experience unauthorized access to files, potential data breaches, or escalation of privileges depending on how the vulnerability is exploited. The impact is further amplified because XML processing is a common feature in web applications, making this attack vector more likely to be encountered in real-world scenarios. The vulnerability demonstrates how seemingly minor input validation issues can create significant security weaknesses that can be exploited by attackers to gain unauthorized access to system resources.
Mitigation strategies for this vulnerability should focus on immediate remediation through Chrome updates to version 116.0.5845.96 or later, which contain the necessary patches to address the XML input validation flaw. Organizations should implement comprehensive patch management procedures to ensure all Chrome installations are updated promptly, as this vulnerability affects a core browser component used by millions of users. Network administrators should consider implementing web filtering solutions that can block access to known malicious domains or content that may attempt to exploit this vulnerability. Browser security policies should be reviewed and enhanced to include additional restrictions on XML processing and file access operations, particularly in environments where users may encounter untrusted content. The implementation of content security policies and sandboxing mechanisms can provide additional layers of protection against exploitation attempts. Security monitoring should include detection of unusual XML processing patterns or attempts to access restricted files through browser-based applications. Organizations should also consider implementing user education programs to raise awareness about phishing attempts that may deliver malicious HTML pages containing crafted XML content. The vulnerability highlights the importance of maintaining up-to-date browser security patches and demonstrates how even medium severity issues can create significant risks when exploited in the right circumstances. Regular security assessments of web applications and browser configurations should be conducted to identify potential exploitation paths and ensure that all security controls are properly implemented.