Bugsinkにおけるevent_idを介したパス・トラバーサル脆弱性

The core of this vulnerability lies in the direct construction of file paths from the eventid input without proper validation. A malicious eventid can be crafted to escape the intended directory, enabling an attacker to write files to unexpected locations on the system. While a valid DSN is required, the potential for DSN discovery, particularly through frontend code exposure, significantly broadens the attack surface. Successful exploitation could lead to data corruption, privilege escalation (depending on file permissions), and potentially even remote code execution if sensitive configuration files are overwritten.

Organizations utilizing Bugsink in environments where DSN credentials are not adequately protected are at heightened risk. This includes deployments with shared hosting configurations, legacy systems with hardcoded DSNs, and applications where DSNs are inadvertently exposed in frontend code. Any system relying on Bugsink for data ingestion should be considered potentially vulnerable.

• python / server: Examine Bugsink logs for unusual file creation or modification events. Look for patterns in event_id parameters that attempt to include directory traversal sequences (e.g., ../).

# Example: Check for suspicious file paths in Bugsink logs
import re
with open('bugsink.log', 'r') as f:
    for line in f:
        if re.search(r'event_id=.*[\/][\/].*', line):
            print(f'Potential Path Traversal attempt: {line}')

• generic web: Monitor access logs for requests to Bugsink endpoints with unusual or long event_id parameters. Check response headers for unexpected file content.

curl -I 'http://bugsink.example.com/ingest?event_id=../../../../etc/passwd' # Check for 403 or other error codes

1. 2025-07-29Disclosure

   disclosure

1. 予約済み2025-07-21
2. 公開日2025-07-29
3. 更新日2025-07-30
4. EPSS 更新日2026-03-23

The primary mitigation for CVE-2025-54433 is to upgrade Bugsink to version 1.7.4 or later, which includes the necessary input validation to prevent path traversal. If immediate upgrading is not feasible, consider implementing stricter access controls on the DSN to limit potential attackers. Review frontend code for any accidental exposure of DSN credentials. Implement a Web Application Firewall (WAF) rule to filter requests containing suspicious characters in the eventid parameter. After upgrading, verify the fix by attempting to submit a crafted eventid designed to traverse outside the intended directory; the ingestion process should reject the request.