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How the CVE Works
The vulnerability in copyparty arises from improper validation of user-supplied regular expressions in the `filter` parameter for the “Recent uploads” page. An attacker can craft a malicious regex pattern, such as (.+)+x, which triggers catastrophic backtracking when processed. This causes excessive CPU consumption, leading to a denial of service (DoS) condition. The server becomes unresponsive, making it inaccessible for legitimate users. The issue is exploitable by default since the feature is enabled without restrictions.
DailyCVE Form
Platform: copyparty
Version: <1.9.3
Vulnerability: ReDoS
Severity: Critical
Date: Aug 4, 2025
Prediction: Patch by Aug 15, 2025
What Undercode Say
Analytics:
curl -X GET "http://localhost:3923/?ru&filter=(.+)+x" grep -i "regex_timeout" /var/log/copyparty.log
Exploit:
import requests
requests.get("http://target:3923/?ru&filter=(.+)+x", timeout=5)
Protection from this CVE:
- Disable regex filtering in config (
allow_regex=False) - Update to copyparty >=1.9.3
- Implement regex timeout limits
Impact:
- Full server unavailability
- CPU exhaustion
- Service disruption
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Sources:
Reported By: github.com
Extra Source Hub:
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