CVE-2024-4976 – CVE-2024-4976 is an out-of-bounds write vulnera... (How to Fix)

Q: What is the severity of CVE-2024-4976?

CVE-2024-4976 has a CVSS score of 5.5 (MEDIUM). CVE-2024-4976 is an out-of-bounds write vulnerability in Xpdf 4.05 and earlier that allows memory corruption through malformed PDF files. Attackers can potentially execute arbitrary code or cause denial of service by exploiting missing object type checks in AcroForm field references. This affects all users processing untrusted PDF files with vulnerable Xpdf versions.

📋 TL;DR

CVE-2024-4976 is an out-of-bounds write vulnerability in Xpdf 4.05 and earlier that allows memory corruption through malformed PDF files. Attackers can potentially execute arbitrary code or cause denial of service by exploiting missing object type checks in AcroForm field references. This affects all users processing untrusted PDF files with vulnerable Xpdf versions.

💻 Affected Systems

Products:

Xpdf

Versions: 4.05 and earlier

Operating Systems: All platforms running Xpdf

Default Config Vulnerable: ⚠️ Yes

Notes: Any application or service using Xpdf libraries to process PDF files is affected.

📦 What is this software?

Xpdf by Xpdfreader

View all CVEs affecting Xpdf →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise when processing malicious PDF files.

🟠

Likely Case

Application crash or denial of service when processing malformed PDF documents.

🟢

If Mitigated

Limited impact with proper sandboxing and memory protection mechanisms in place.

🌐 Internet-Facing: MEDIUM - Requires user interaction to open malicious PDFs, but common in web applications processing uploaded files.

🏢 Internal Only: LOW - Primarily affects systems processing PDFs from untrusted sources, less common in internal-only workflows.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires crafting malicious PDF files that trigger the vulnerability when processed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Xpdf 4.06

Vendor Advisory: https://www.xpdfreader.com/security-bug/CVE-2024-4976.html

Restart Required: No

Instructions:

1. Download Xpdf 4.06 or later from xpdfreader.com. 2. Replace existing Xpdf installation with patched version. 3. Recompile any applications using Xpdf libraries with updated version.

🔧 Temporary Workarounds

Disable PDF processing

all

Temporarily disable Xpdf-based PDF processing until patching is complete.

Use alternative PDF renderer

all

Switch to alternative PDF processing libraries like Poppler or MuPDF.

🧯 If You Can't Patch

Implement strict input validation for PDF files before processing
Run Xpdf in sandboxed/containerized environments with minimal privileges

🔍 How to Verify

Check if Vulnerable:

Check Xpdf version with 'xpdf -v' command or examine application dependencies.

Check Version:

xpdf -v

Verify Fix Applied:

Confirm Xpdf version is 4.06 or later using 'xpdf -v' command.

📡 Detection & Monitoring

Log Indicators:

Application crashes with segmentation faults
Memory access violation errors in logs

Network Indicators:

Unusual PDF file uploads to web applications
PDF processing failures in network services

SIEM Query:

source="application.log" AND ("segmentation fault" OR "memory violation") AND process="xpdf"

📊 Metadata

CVE ID: CVE-2024-4976

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-787

Published: May 15, 2024

Last Updated: January 29, 2025

🔗 References

https://www.xpdfreader.com/security-bug/CVE-2024-4976.html Vendor Advisory
https://www.xpdfreader.com/security-bug/CVE-2024-4976.html Vendor Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2024-4976, you might also want to check these: