CVE-2020-6624 – CVE-2020-6624 is a heap-based buffer over-read ... (How to Fix)

Q: What is the severity of CVE-2020-6624?

CVE-2020-6624 has a CVSS score of 7.1 (HIGH). CVE-2020-6624 is a heap-based buffer over-read vulnerability in jhead's process_DQT function that could allow attackers to read sensitive memory contents. This affects users processing JPEG files with vulnerable versions of jhead, potentially exposing system information or causing crashes.

📋 TL;DR

CVE-2020-6624 is a heap-based buffer over-read vulnerability in jhead's process_DQT function that could allow attackers to read sensitive memory contents. This affects users processing JPEG files with vulnerable versions of jhead, potentially exposing system information or causing crashes.

💻 Affected Systems

Products:

jhead

Versions: Through 3.04

Operating Systems: Linux, Unix-like systems, Windows (if compiled from source)

Default Config Vulnerable: ⚠️ Yes

Notes: Affects all installations using vulnerable jhead versions to process JPEG files; commonly found in Linux distributions and image processing pipelines.

📦 What is this software?

Jhead by Jhead Project

View all CVEs affecting Jhead →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Information disclosure leading to memory content leakage, potential denial of service through application crashes, or as a stepping stone for more complex attacks.

🟠

Likely Case

Application crash or denial of service when processing malicious JPEG files, with possible limited information disclosure.

🟢

If Mitigated

Minimal impact if proper input validation and memory protections are in place, though crashes may still occur.

🌐 Internet-Facing: MEDIUM - jhead is commonly used for image processing but typically not directly internet-facing; risk exists if web applications use it to process user-uploaded images.

🏢 Internal Only: LOW - Primarily affects systems processing JPEG files with jhead; limited to specific use cases.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires processing a malicious JPEG file; proof-of-concept details are publicly available in bug reports.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 3.04.1 and later

Vendor Advisory: https://security.gentoo.org/glsa/202007-17

Restart Required: No

Instructions:

1. Update jhead to version 3.04.1 or later using your package manager. 2. For Linux: Use 'sudo apt update && sudo apt upgrade jhead' (Debian/Ubuntu) or 'sudo yum update jhead' (RHEL/CentOS). 3. Verify the update with 'jhead -V'.

🔧 Temporary Workarounds

Restrict JPEG file processing

all

Limit jhead usage to trusted JPEG files only; implement file validation before processing.

Use alternative image tools

all

Temporarily replace jhead with alternative JPEG processing tools like exiftool or imagemagick.

🧯 If You Can't Patch

Implement strict input validation for JPEG files before processing with jhead
Isolate jhead usage in sandboxed environments or containers

🔍 How to Verify

Check if Vulnerable:

Check jhead version with 'jhead -V' or 'jhead --version'; if version is 3.04 or earlier, it's vulnerable.

Check Version:

jhead -V

Verify Fix Applied:

After updating, run 'jhead -V' to confirm version is 3.04.1 or later.

📡 Detection & Monitoring

Log Indicators:

Application crashes or segmentation faults when processing JPEG files
Unexpected memory access errors in system logs

Network Indicators:

Unusual file uploads to systems using jhead for image processing

SIEM Query:

Process:jhead AND (EventID:1000 OR Signal:SIGSEGV)

📊 Metadata

CVE ID: CVE-2020-6624

CVSS v3 Score: 7.1 (HIGH)

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

CWE: CWE-125

Published: January 9, 2020

Last Updated: November 21, 2024

🔗 References

https://bugs.gentoo.org/711220#c3 Issue Tracking,Third Party Advisory
https://bugs.gentoo.org/876247#c0 Issue Tracking,Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/jhead/+bug/1858744 Exploit,Issue Tracking,Third Party Advisory
https://security.gentoo.org/glsa/202007-17 Third Party Advisory
https://bugs.gentoo.org/711220#c3 Issue Tracking,Third Party Advisory
https://bugs.gentoo.org/876247#c0 Issue Tracking,Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/jhead/+bug/1858744 Exploit,Issue Tracking,Third Party Advisory
https://security.gentoo.org/glsa/202007-17 Third Party Advisory

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🔗 Related Vulnerabilities

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