CVE-2020-21428 – A buffer overflow vulnerability in FreeImage's ... (How to Fix)

Q: What is the severity of CVE-2020-21428?

CVE-2020-21428 has a CVSS score of 7.8 (HIGH). A buffer overflow vulnerability in FreeImage's DDS plugin allows remote attackers to execute arbitrary code by tricking a user or system into processing a specially crafted image file. This affects any application using FreeImage 3.18.0 to load DDS images. Attackers could gain control of affected systems.

📋 TL;DR

A buffer overflow vulnerability in FreeImage's DDS plugin allows remote attackers to execute arbitrary code by tricking a user or system into processing a specially crafted image file. This affects any application using FreeImage 3.18.0 to load DDS images. Attackers could gain control of affected systems.

💻 Affected Systems

Products:

FreeImage

Versions: 3.18.0

Operating Systems: All platforms where FreeImage runs (Linux, Windows, macOS)

Default Config Vulnerable: ⚠️ Yes

Notes: Any application that uses FreeImage library to load DDS image files is vulnerable.

📦 What is this software?

Freeimage by Freeimage Project

View all CVEs affecting Freeimage →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, or ransomware deployment.

🟠

Likely Case

Application crash (denial of service) or limited code execution in the context of the vulnerable application.

🟢

If Mitigated

Application crash with no further impact if memory protections (ASLR, DEP) are effective.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires user or system to process a malicious DDS file. Public proof-of-concept exists in bug reports.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 3.19.0 or later

Vendor Advisory: https://sourceforge.net/p/freeimage/bugs/299/

Restart Required: Yes

Instructions:

1. Upgrade FreeImage to version 3.19.0 or later. 2. Rebuild or update any applications using FreeImage. 3. Restart affected services or applications.

🔧 Temporary Workarounds

Disable DDS plugin

all

Remove or disable FreeImage's DDS plugin to prevent loading of DDS files.

rm /usr/lib/freeimage/PluginDDS.*
mv PluginDDS.cpp PluginDDS.cpp.disabled

Input validation

all

Implement strict file type validation to reject DDS files from untrusted sources.

🧯 If You Can't Patch

Implement network segmentation to isolate systems using FreeImage.
Use application allowlisting to prevent execution of unknown processes.

🔍 How to Verify

Check if Vulnerable:

Check FreeImage version: `freeimage-config --version` or examine library files.

Check Version:

freeimage-config --version

Verify Fix Applied:

Confirm FreeImage version is 3.19.0 or later.

📡 Detection & Monitoring

Log Indicators:

Application crashes when processing DDS files
Unexpected process execution from image processing applications

Network Indicators:

Unusual outbound connections from systems processing images

SIEM Query:

source="application.log" "FreeImage" AND ("crash" OR "segfault") AND "DDS"

📊 Metadata

CVE ID: CVE-2020-21428

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-120

Published: August 22, 2023

Last Updated: May 2, 2025

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2020-21428, you might also want to check these: