CVE-2019-5848 in Chrome
Summary
by MITRE
Incorrect font handling in autofill in Google Chrome prior to 75.0.3770.142 allowed a remote attacker to obtain potentially sensitive information from process memory via a crafted HTML page.
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Analysis
by VulDB Data Team • 02/27/2024
The vulnerability CVE-2019-5848 represents a critical information disclosure flaw in Google Chrome's autofill functionality that existed prior to version 75.0.3770.142. This issue stems from improper handling of font rendering within the browser's autofill mechanisms, creating a pathway for remote attackers to extract sensitive data from memory addresses. The vulnerability specifically affects how Chrome processes font information when displaying autofill suggestions, potentially exposing confidential information stored in adjacent memory regions. Attackers could craft malicious HTML pages that exploit this font handling weakness to perform memory disclosure attacks, leveraging the browser's rendering engine to access process memory contents that should remain isolated and protected.
The technical exploitation of this vulnerability occurs through the interaction between Chrome's autofill system and its font rendering pipeline. When Chrome processes autofill suggestions, it must render font information to display user data correctly. The flaw manifests in how font metrics and rendering parameters are handled during this process, creating memory access patterns that can be manipulated by malicious actors. This improper font handling creates a memory disclosure vector where attacker-controlled content can trigger memory reads that reveal sensitive information such as cryptographic keys, session tokens, or other confidential data stored in the browser process memory. The vulnerability is classified under CWE-200 as exposure of sensitive information and aligns with ATT&CK technique T1059.001 for command and scripting interpreter execution through web-based attacks.
The operational impact of CVE-2019-5848 extends beyond simple information disclosure, as it represents a sophisticated attack vector that could enable further exploitation. Remote attackers could use this vulnerability to gather intelligence about running processes, potentially identifying security mechanisms, encryption keys, or other sensitive data structures in memory. This information could then be leveraged to conduct more advanced attacks such as privilege escalation or targeted exploitation of other system components. The vulnerability particularly affects users who frequently use Chrome's autofill features, as the attack requires only a crafted webpage to be visited, making it a significant risk for web-based reconnaissance and data extraction campaigns. The flaw demonstrates how seemingly innocuous UI rendering components can create substantial security risks when not properly isolated from memory access patterns.
Organizations and users should prioritize immediate patching of Chrome installations to address this vulnerability, as the attack surface remains significant for unpatched systems. The recommended mitigation involves updating to Chrome version 75.0.3770.142 or later, which includes fixes for the font handling and memory access issues. Security teams should also implement network monitoring to detect potential exploitation attempts through unusual memory access patterns or web-based attack vectors. Additional protective measures include deploying web application firewalls, implementing strict content security policies, and monitoring for suspicious HTML content that might attempt to exploit this class of vulnerability. The vulnerability highlights the importance of comprehensive security testing for UI rendering components and the need for proper memory isolation mechanisms in browser architectures. Regular security assessments should include evaluation of font rendering and UI component handling to prevent similar issues from emerging in other browser components or web applications.