CVE-2021-3401
📋 TL;DR
This vulnerability in Bitcoin Core could allow remote code execution when malicious arguments are passed to the bitcoin-qt program through unsafe URI handling. It affects Bitcoin Core versions before 0.19.0 when used with desktop environments or web browsers that improperly handle bitcoin:// URIs. The discoverer notes uncertainty about actual exploitability.
💻 Affected Systems
- Bitcoin Core
📦 What is this software?
Bitcoin by Bitcoin
⚠️ Risk & Real-World Impact
Worst Case
Remote attackers could execute arbitrary code with the privileges of the Bitcoin Core user, potentially leading to full system compromise, theft of cryptocurrency, or installation of malware.
Likely Case
Limited impact due to the specific conditions required for exploitation and the discoverer's doubts about actual exploitability; most likely would result in denial of service or failed exploitation attempts.
If Mitigated
No impact if using Bitcoin Core 0.19.0 or later, or if URI handlers are properly configured to avoid passing unsafe arguments.
🎯 Exploit Status
The vulnerability requires specific conditions and the original discoverer expressed doubts about actual exploitability. No known public exploits exist.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.19.0 and later
Vendor Advisory: https://github.com/bitcoin/bitcoin/security/advisories/GHSA-5v2v-7v9m-8c5h
Restart Required: Yes
Instructions:
1. Download Bitcoin Core 0.19.0 or later from bitcoin.org. 2. Stop the Bitcoin Core application. 3. Install the new version. 4. Restart Bitcoin Core.
🔧 Temporary Workarounds
Disable unsafe URI handlers
allConfigure desktop environments and web browsers to not pass unsafe arguments when handling bitcoin:// URIs
Use command-line interface only
allAvoid using bitcoin-qt GUI and use bitcoind command-line interface instead
🧯 If You Can't Patch
- Isolate Bitcoin Core systems from untrusted networks and applications
- Implement strict application whitelisting to prevent unauthorized applications from interacting with Bitcoin Core
🔍 How to Verify
Check if Vulnerable:
Check Bitcoin Core version: bitcoin-qt --version or bitcoind --version. If version is below 0.19.0, the system is vulnerable.Check Version:
bitcoin-qt --version || bitcoind --versionVerify Fix Applied:
After updating, verify version is 0.19.0 or higher using bitcoin-qt --version or bitcoind --version.📡 Detection & Monitoring
Log Indicators:
- Unusual process launches from bitcoin-qt
- Error messages related to -platformpluginpath argument
- Failed URI handler invocations
Network Indicators:
- Unusual network connections originating from Bitcoin Core process
SIEM Query:
process_name:bitcoin-qt AND (command_line:*platformpluginpath* OR parent_process:*desktop* OR parent_process:*browser*)