CVE-2021-31503 – CVE-2021-31503 is a remote code execution vulne... (How to Fix)

Q: What is the severity of CVE-2021-31503?

CVE-2021-31503 has a CVSS score of 7.8 (HIGH). CVE-2021-31503 is a remote code execution vulnerability in OpenText Brava! Desktop that allows attackers to execute arbitrary code by tricking users into opening malicious IGS files. The vulnerability exists due to improper pointer initialization during IGS file parsing. Users of affected OpenText Brava! Desktop versions are at risk.

📋 TL;DR

CVE-2021-31503 is a remote code execution vulnerability in OpenText Brava! Desktop that allows attackers to execute arbitrary code by tricking users into opening malicious IGS files. The vulnerability exists due to improper pointer initialization during IGS file parsing. Users of affected OpenText Brava! Desktop versions are at risk.

💻 Affected Systems

Products:

OpenText Brava! Desktop

Versions: Build 16.6.3.84 (package 16.6.3.134) and likely earlier versions

Operating Systems: Windows

Default Config Vulnerable: ⚠️ Yes

Notes: Vulnerability is in the IGS file parser component. All installations with this version are vulnerable by default.

📦 What is this software?

Brava\! Desktop by Opentext

View all CVEs affecting Brava\! Desktop →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system compromise with attacker gaining full control of the victim's machine in the context of the current user.

🟠

Likely Case

Malware installation, data theft, or ransomware deployment through crafted IGS files.

🟢

If Mitigated

Limited impact if proper application sandboxing, least privilege principles, and file validation are implemented.

🌐 Internet-Facing: MEDIUM - Requires user interaction to open malicious files, but these could be delivered via email, downloads, or compromised websites.

🏢 Internal Only: MEDIUM - Similar risk internally if users open untrusted IGS files from network shares or internal systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires user interaction (opening malicious file) but the vulnerability itself is unauthenticated. ZDI-CAN-12690 suggests active research.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Later versions than 16.6.3.84

Vendor Advisory: https://www.opentext.com/products/brava

Restart Required: Yes

Instructions:

1. Check current Brava! Desktop version. 2. Download and install latest version from OpenText support portal. 3. Restart system after installation. 4. Verify update completed successfully.

🔧 Temporary Workarounds

Disable IGS file association

windows

Remove Brava! Desktop as default handler for IGS files to prevent automatic exploitation

Control Panel > Default Programs > Associate a file type or protocol with a program > Select .igs > Change program > Choose different application

Block IGS files at perimeter

all

Configure email and web gateways to block .igs file attachments

🧯 If You Can't Patch

Implement application whitelisting to prevent unauthorized executables from running
Run Brava! Desktop with restricted user privileges (non-admin account)

🔍 How to Verify

Check if Vulnerable:

Check Help > About in Brava! Desktop for version 16.6.3.84 or earlier

Check Version:

In Brava! Desktop: Help > About

Verify Fix Applied:

Verify version is newer than 16.6.3.84 and test opening known safe IGS files

📡 Detection & Monitoring

Log Indicators:

Multiple failed IGS file parsing attempts
Unexpected process creation from BravaDesktop.exe

Network Indicators:

Downloads of IGS files from untrusted sources
Outbound connections from Brava! Desktop to suspicious IPs

SIEM Query:

Process Creation where Image contains 'BravaDesktop.exe' and CommandLine contains '.igs'

📊 Metadata

CVE ID: CVE-2021-31503

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-824

Published: August 3, 2021

Last Updated: November 21, 2024

🔗 References

https://www.zerodayinitiative.com/advisories/ZDI-21-645/ Third Party Advisory,VDB Entry
https://www.cvedetails.com/vulnerability-list/vendor_id-2032/product_id-96672/Opentext-Brava-Desktop.html?page=1&opec=1&order=1&trc=35&sha=37f4ed0596f8ccacca7d571f22a38c97b0f19f4c Third Party Advisory
https://www.opentext.com/products/brava Product
https://www.zerodayinitiative.com/advisories/ZDI-21-645/ Third Party Advisory,VDB Entry

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🔗 Related Vulnerabilities

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