CVE-2024-7018: Google Chrome Buffer Overflow Vulnerability

CVE-2024-7018 Overview

CVE-2024-7018 is a heap buffer overflow vulnerability in the PDF component of Google Chrome versions prior to 124.0.6367.78. A remote attacker can exploit heap corruption by delivering a crafted PDF file to a target user. Chromium classifies the security severity as Medium, while the National Vulnerability Database assigns a CVSS 3.1 base score of 7.8 (High). The flaw maps to CWE-122 (Heap-based Buffer Overflow) and CWE-787 (Out-of-bounds Write). Successful exploitation requires user interaction, typically opening or rendering the malicious PDF inside the browser.

Critical Impact
A crafted PDF processed by Chrome's PDF engine can corrupt heap memory and lead to arbitrary code execution within the renderer process.

Affected Products

Google Chrome versions prior to 124.0.6367.78
Chromium-based browsers sharing the same PDFium component
Embedded applications using affected Chromium builds for PDF rendering

Discovery Timeline

2024-09-23 - CVE-2024-7018 published to the National Vulnerability Database
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2024-7018

Vulnerability Analysis

The vulnerability resides in Chrome's PDF rendering subsystem, which is implemented through the PDFium library. PDFium parses untrusted PDF objects, streams, and embedded resources during document rendering. A malformed structure inside a crafted PDF triggers an out-of-bounds write on the heap. The resulting heap corruption can overwrite adjacent allocator metadata or object pointers used by the renderer. An attacker who controls the corrupted memory can pivot from heap corruption to arbitrary code execution inside the renderer sandbox. The Chromium issue tracker entry 333414305 tracks the underlying defect and the corresponding fix.

Root Cause

The root cause is insufficient bounds validation when PDFium processes specific PDF structures. The code path writes beyond the allocated heap buffer, producing the conditions described by CWE-122 and CWE-787. Memory tags and adjacent allocations become attacker-influenced state once the write occurs.

Attack Vector

Exploitation requires a user to open a crafted PDF in a vulnerable Chrome build or to visit a web page that embeds the PDF. The CVSS vector indicates local attack vector with required user interaction. No authentication is required, and the impact spans confidentiality, integrity, and availability. The EPSS probability is 0.24% with a percentile of 14.896, and no public proof-of-concept or in-the-wild exploitation is currently tracked.

No verified exploit code is available. Refer to the Chromium Issue Tracker entry 333414305 for technical details once the bug becomes publicly visible.

Detection Methods for CVE-2024-7018

Indicators of Compromise

Chrome renderer processes crashing with heap corruption signatures shortly after opening PDF content
PDF files arriving through email, chat, or download channels with malformed object streams or oversized cross-reference tables
Unexpected child processes spawned by chrome.exe immediately after PDF rendering
Outbound network connections from a renderer process to previously unseen domains after PDF viewing

Detection Strategies

Inventory installed Chrome versions across the fleet and flag any build older than 124.0.6367.78
Inspect PDF attachments for malformed structures using static document analyzers prior to user delivery
Correlate browser crash telemetry with PDF MIME type loads to surface candidate exploitation attempts
Monitor sandbox escape indicators such as token manipulation or unexpected process injection from renderer processes

Monitoring Recommendations

Forward Chrome crash reports and Windows Error Reporting events to a central log platform for analysis
Track endpoint browser version inventory and alert when hosts fall behind the patched build
Enable EDR rules that flag anomalous code execution originating from browser renderer processes
Audit web proxy and email gateway logs for PDF downloads from low-reputation sources

How to Mitigate CVE-2024-7018

Immediate Actions Required

Update Google Chrome to version 124.0.6367.78 or later on all managed endpoints
Restart browsers after the update to ensure the patched binaries are loaded
Apply equivalent updates to Chromium-based browsers and embedded WebView components
Restrict PDF attachments from untrusted external senders at the email gateway until patching completes

Patch Information

Google resolved CVE-2024-7018 in Chrome 124.0.6367.78. Administrators should validate deployment through enterprise update channels such as Google Update, Microsoft Intune, or Jamf. Track remediation status against the Chromium Issue Tracker entry.

Workarounds

Configure Chrome enterprise policy AlwaysOpenPdfExternally to route PDFs to a hardened external viewer until patching is verified
Disable the built-in PDF viewer through group policy on systems that cannot update immediately
Enforce site isolation and renderer sandboxing through enterprise policy to limit the blast radius of renderer compromise
Block PDF rendering from untrusted origins using web filtering or content disarm and reconstruction tooling

bash

# Configuration example: enterprise policy to disable Chrome's internal PDF viewer
# Windows registry path
HKLM\Software\Policies\Google\Chrome\AlwaysOpenPdfExternally = 1

# macOS plist
defaults write com.google.Chrome AlwaysOpenPdfExternally -bool true