CVE-2025-67125
📋 TL;DR
This CVE describes a signed integer overflow vulnerability in docopt.cpp v0.6.2 that occurs when merging occurrence counters. Attackers can bypass logic/policy controls in applications that rely on occurrence-based limits, potentially allowing them to exceed rate limits or safety restrictions. Applications using the affected docopt.cpp library for command-line argument parsing with occurrence counters are vulnerable.
💻 Affected Systems
- docopt.cpp
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete bypass of application security controls, allowing unlimited command execution, privilege escalation, or circumvention of safety mechanisms designed to limit user actions.
Likely Case
Bypass of rate limiting or usage restrictions in applications that use occurrence counters for command-line arguments, potentially allowing users to exceed intended limits.
If Mitigated
Minimal impact if applications don't use occurrence counters or have additional validation layers beyond the library's counting mechanism.
🎯 Exploit Status
Exploitation requires understanding of the target application's argument structure and usage of occurrence counters. The gist reference shows technical details but not a complete weaponized exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 0.6.3 or later
Vendor Advisory: https://github.com/docopt/docopt.cpp
Restart Required: Yes
Instructions:
1. Check current docopt.cpp version in your project. 2. Update to version 0.6.3 or later via package manager or direct update. 3. Recompile and rebuild your application. 4. Restart affected services.
🔧 Temporary Workarounds
Disable occurrence counters
allModify application code to avoid using occurrence counters for command-line arguments
Modify source code to use boolean flags instead of counting occurrences
Input validation wrapper
allAdd pre-parsing validation to limit argument counts before passing to docopt.cpp
Implement custom argument validation that checks counts before docopt parsing
🧯 If You Can't Patch
- Implement application-level validation of argument counts after parsing
- Use compiler hardening options like -ftrapv to crash on overflow (trading DoS for security bypass)
🔍 How to Verify
Check if Vulnerable:
Check if your application uses docopt.cpp version 0.6.2 and uses occurrence counters (arguments that can appear multiple times with counting semantics)Check Version:
Check your build system or package manager for docopt.cpp version, or examine the library header files for version informationVerify Fix Applied:
Verify docopt.cpp version is 0.6.3 or later and test that occurrence counters now properly handle maximum values📡 Detection & Monitoring
Log Indicators:
- Unexpected high counts of command-line arguments
- Application errors related to integer overflow or argument parsing
Network Indicators:
- N/A - This is a local command-line parsing vulnerability
SIEM Query:
Look for process execution logs with unusually high repetition of command-line flags or arguments