CVE-2023-5474: Google Chrome Buffer Overflow Vulnerability

CVE-2023-5474 Overview

CVE-2023-5474 is a heap buffer overflow vulnerability in the PDF rendering component of Google Chrome prior to version 118.0.5993.70. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption via a specially crafted PDF file, requiring the victim to engage in specific user interactions such as opening a malicious PDF document.

The vulnerability stems from improper bounds checking when processing PDF content, which can lead to out-of-bounds memory writes on the heap. Successful exploitation could allow an attacker to execute arbitrary code within the context of the browser process or cause a denial of service condition.

Critical Impact

Remote attackers can achieve code execution through heap corruption by delivering malicious PDF files to victims, potentially leading to full system compromise.

Affected Products

• Google Chrome versions prior to 118.0.5993.70
• Debian Linux 11.0
• Debian Linux 12.0

Discovery Timeline

• 2023-10-11 - CVE-2023-5474 published to NVD
• 2025-05-01 - Last updated in NVD database

Technical Details for CVE-2023-5474

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption issue that occurs when the PDF rendering engine writes data beyond the boundaries of an allocated heap buffer. In the context of Google Chrome's PDF processing, this can occur when parsing malformed or specially crafted PDF structures that cause the parser to miscalculate buffer sizes or write indices.

The heap buffer overflow in Chrome's PDF component can be triggered through user interaction with a malicious PDF file. The exploitation requires social engineering to convince users to open the crafted document, but once triggered, the vulnerability provides a powerful primitive for attackers seeking to achieve code execution.

Root Cause

The root cause is improper validation of data sizes or indices during PDF parsing operations. When the PDF renderer processes certain malformed PDF structures, it fails to properly validate boundaries before writing data to heap-allocated buffers. This oversight allows attackers to craft PDF files that cause writes beyond allocated buffer boundaries, corrupting adjacent heap memory.

Attack Vector

The attack vector is network-based, requiring user interaction. An attacker would typically deliver the malicious PDF file through:

1. Email attachments with crafted PDF files
2. Malicious websites hosting the PDF for download
3. Drive-by download scenarios where users are tricked into opening PDF content
4. Compromised legitimate websites serving malicious PDF files

When a victim opens the malicious PDF in an affected version of Chrome, the heap overflow is triggered during the parsing process. The attacker can leverage the heap corruption to potentially gain control of program execution flow.

Since no verified code examples are available for this vulnerability, the specific exploitation technique involves crafting PDF object streams or content streams that cause the PDF parser to write beyond allocated heap buffers. Technical details can be found in the Chromium Bug Report #1483194.

Detection Methods for CVE-2023-5474

Indicators of Compromise

• Unusual Chrome browser crashes when opening PDF files
• Memory access violations or heap corruption errors in Chrome crash logs
• Suspicious PDF files with malformed object streams or unexpected sizes
• Chrome renderer process crashes with heap-related error signatures

Detection Strategies

• Monitor for Chrome browser crashes that occur specifically when PDF files are opened or rendered
• Implement endpoint detection for suspicious PDF file characteristics including oversized objects or malformed structures
• Deploy network-based inspection for PDF files being downloaded that exhibit anomalous structural patterns
• Utilize SentinelOne's behavioral AI to detect exploitation attempts targeting browser memory corruption

Monitoring Recommendations

• Enable Chrome crash reporting and analyze crash dumps for heap corruption signatures
• Monitor endpoint telemetry for unusual browser process behavior during PDF rendering
• Track Chrome version deployment across the organization to identify unpatched systems
• Implement logging for PDF file access patterns to identify potential attack campaigns

How to Mitigate CVE-2023-5474

Immediate Actions Required

• Update Google Chrome to version 118.0.5993.70 or later immediately across all systems
• Review and apply relevant security advisories from Debian (DSA-5526) and Gentoo (GLSA 202311-11)
• Consider disabling automatic PDF rendering in Chrome while patching is in progress
• Alert users to avoid opening PDF files from untrusted sources until systems are patched

Patch Information

Google has released Chrome version 118.0.5993.70 which addresses this vulnerability. The patch is available through Chrome's automatic update mechanism and can be manually downloaded from official Google sources.

Vendor Advisory:Google Chrome Desktop Update

Distribution Security Advisories:

• Debian Security Advisory DSA-5526
• Gentoo GLSA 202311-11
• Gentoo GLSA 202312-07
• Gentoo GLSA 202401-34

Workarounds

• Configure Chrome to download PDF files instead of opening them inline, reducing automatic exposure to malicious content
• Use an alternative PDF viewer for untrusted documents until Chrome is updated
• Implement network-level filtering to scan PDF attachments and downloads for malicious characteristics
• Consider browser isolation solutions that render untrusted content in sandboxed environments

# Verify Chrome version to ensure patch is applied
google-chrome --version
# Should show version 118.0.5993.70 or higher

# Force Chrome update check (Linux)
sudo apt update && sudo apt upgrade google-chrome-stable

# Alternative: Check Chrome version via browser
# Navigate to chrome://settings/help