CVE-2024-43380
📋 TL;DR
CVE-2024-43380 is a denial-of-service vulnerability in fugit's natural language time parser. The parser accepts arbitrarily long input strings without validation, causing indefinite thread blocking during parsing. Applications using fugit without input length validation are affected.
💻 Affected Systems
- fugit
- flor
- any application using fugit for natural language time parsing
📦 What is this software?
Fugit by Floraison
⚠️ Risk & Real-World Impact
Worst Case
Complete service unavailability due to thread exhaustion from maliciously crafted long input strings, leading to denial of service.
Likely Case
Degraded performance or temporary service disruption when processing unusually long natural language time strings.
If Mitigated
Minimal impact with input validation limiting string length before parsing.
🎯 Exploit Status
Exploitation requires submitting a specially crafted long string to the natural language parser. No authentication needed if parser accepts external input.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.11.1
Vendor Advisory: https://github.com/floraison/fugit/security/advisories/GHSA-2m96-52r3-2f3g
Restart Required: Yes
Instructions:
1. Update fugit gem to version 1.11.1 or later. 2. Run 'bundle update fugit' if using Bundler. 3. Restart the application server. 4. Verify the update with 'bundle show fugit' or checking Gemfile.lock.
🔧 Temporary Workarounds
Input length validation
allAdd input validation to limit string length before passing to fugit parser
# Ruby example: validate input length before parsing
if time_string.length > 100
raise 'Input too long'
end
Fugit.parse_nat(time_string)
🧯 If You Can't Patch
- Implement strict input validation limiting natural language time strings to reasonable lengths (e.g., < 100 characters)
- Disable natural language parsing functionality if not essential, or restrict to trusted/internal sources only
🔍 How to Verify
Check if Vulnerable:
Check fugit gem version with 'gem list fugit' or 'bundle show fugit'. If version is < 1.11.1 and application uses natural language parsing with user input, it's vulnerable.Check Version:
gem list fugit | grep fugit or bundle show fugitVerify Fix Applied:
After updating, test with a long input string to ensure parser returns promptly or rejects the input. Verify version is ≥ 1.11.1.📡 Detection & Monitoring
Log Indicators:
- Unusually long processing times for time parsing operations
- Thread blocking warnings
- Increased CPU usage without corresponding request completion
Network Indicators:
- Timeouts on endpoints accepting time string inputs
- Unusually long request/response times for specific API calls
SIEM Query:
source="application.log" AND ("fugit" OR "parse_nat") AND duration > 10s