CVE-2023-5841 – This vulnerability allows attackers to execute ... (How to Fix)

Q: What is the severity of CVE-2023-5841?

CVE-2023-5841 has a CVSS score of 9.1 (CRITICAL). This vulnerability allows attackers to execute arbitrary code or cause denial of service by exploiting a heap-based buffer overflow in OpenEXR image parsing library. It affects any application that processes malicious OpenEXR files containing deep scanline data. Users of OpenEXR library versions 3.2.1 and earlier are vulnerable.

📋 TL;DR

This vulnerability allows attackers to execute arbitrary code or cause denial of service by exploiting a heap-based buffer overflow in OpenEXR image parsing library. It affects any application that processes malicious OpenEXR files containing deep scanline data. Users of OpenEXR library versions 3.2.1 and earlier are vulnerable.

💻 Affected Systems

Products:

Academy Software Foundation OpenEXR

Versions: 3.2.1 and prior versions

Operating Systems: All platforms running vulnerable OpenEXR library

Default Config Vulnerable: ⚠️ Yes

Notes: Any application linking against vulnerable OpenEXR library versions is affected when processing OpenEXR files.

📦 What is this software?

Openexr by Openexr

View all CVEs affecting Openexr →

⚠️ 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) with potential for code execution in memory-unsafe environments.

🟢

If Mitigated

Application crash with no code execution if ASLR/DEP/other memory protections are effective.

🌐 Internet-Facing: HIGH - Any service accepting user-uploaded OpenEXR files is vulnerable to remote exploitation.

🏢 Internal Only: MEDIUM - Internal users could exploit via malicious files, but requires user interaction or file processing.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Proof-of-concept exploit details are publicly available in disclosure references. Exploitation requires only a malicious OpenEXR file.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: v3.2.2 or v3.1.12

Vendor Advisory: https://github.com/AcademySoftwareFoundation/openexr/security/advisories

Restart Required: Yes

Instructions:

1. Identify OpenEXR version in use. 2. Update to v3.2.2 or v3.1.12 via package manager or source compilation. 3. Restart all applications using OpenEXR library.

🔧 Temporary Workarounds

Disable OpenEXR file processing

all

Block or reject OpenEXR files at application or network perimeter

Use memory protection controls

all

Enable ASLR, DEP, and other memory corruption mitigations

🧯 If You Can't Patch

Implement strict file type validation to reject OpenEXR files
Isolate vulnerable systems in network segments with limited access

🔍 How to Verify

Check if Vulnerable:

Check OpenEXR library version: ldd /path/to/application | grep OpenEXR, then check version with package manager

Check Version:

pkg-config --modversion OpenEXR or check library file properties

Verify Fix Applied:

Verify OpenEXR version is v3.2.2 or v3.1.12 or later

📡 Detection & Monitoring

Log Indicators:

Application crashes when processing image files
Memory access violation errors in logs

Network Indicators:

Unexpected OpenEXR file uploads to services
Large number of image processing requests

SIEM Query:

source="application.logs" AND ("segmentation fault" OR "access violation") AND process="*openexr*"

📊 Metadata

CVE ID: CVE-2023-5841

CVSS v3 Score: 9.1 (CRITICAL)

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

CWE: CWE-122

Published: February 1, 2024

Last Updated: November 4, 2025

🔗 References

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