- Description: An attacker with access to the MailCatcher web interface (either legitimately or illegitimately) can view all captured emails. The attacker might browse through the emails, searching for sensitive information like passwords, API keys, personally identifiable information (PII), internal URLs, or database connection strings that were inadvertently included in email content during testing.
- Impact: Compromise of sensitive data, leading to potential account takeovers, data breaches, unauthorized access to internal systems, and reputational damage.
- Affected Component: MailCatcher Web Interface (
/route and associated rendering logic), Email Storage (in-memory or SQLite database), Email Parsing (extracting headers and body). - Risk Severity: Critical
- Mitigation Strategies:
- Data Sanitization: Ensure test data used in the application never includes real sensitive information. Use mock data or data anonymization techniques.
- Input Validation (Application-Side): Prevent the application from sending sensitive data in emails in the first place. Validate and sanitize all data before it's included in email bodies or headers.
- Regular Purging: Frequently delete emails from MailCatcher, either manually or through automated scripts.
- Network Access Control: Restrict access to the MailCatcher web interface to authorized users/IP addresses only (see below).
- Description: An attacker gains access to the MailCatcher web interface because it's exposed to an untrusted network (e.g., the public internet or a less secure internal network segment). The attacker could be an external party or an internal user without legitimate access. They can then view all captured emails.
- Impact: Same as "Sensitive Data Exposure in Captured Emails" - compromise of sensitive data.
- Affected Component: MailCatcher Web Interface (entire web server component, including routing and authentication – or lack thereof).
- Risk Severity: Critical
- Mitigation Strategies:
- Firewall Rules: Use a firewall (e.g.,
iptables,ufw, or a cloud provider's firewall) to restrict access to the MailCatcher web interface's port (default 1080) to only trusted IP addresses or networks (e.g., localhost, developer workstations, VPN). - Containerization: Run MailCatcher within a Docker container and carefully control the container's network exposure. Only expose the necessary ports to the host or other containers.
- Reverse Proxy with Authentication: (Less critical if firewall rules are in place) Use a reverse proxy like Nginx or Apache to add authentication (e.g., basic auth, OAuth) to the MailCatcher interface.
- VPN: Access Mailcatcher only through VPN.
- Firewall Rules: Use a firewall (e.g.,
- Description: An attacker exploits a vulnerability in MailCatcher itself (e.g., a buffer overflow in the email parsing logic, a cross-site scripting (XSS) vulnerability in the web interface, or a remote code execution vulnerability). The attacker could craft a malicious email or HTTP request to trigger the vulnerability.
- Impact: Could range from denial of service (crashing MailCatcher) to arbitrary code execution on the host system, potentially leading to complete system compromise.
- Affected Component: Depends on the specific vulnerability. Could be any part of MailCatcher, including the SMTP server, web server, email parsing logic, or database interaction.
- Risk Severity: High (potentially Critical, depending on the vulnerability)
- Mitigation Strategies:
- Keep Updated: Regularly update MailCatcher to the latest version to patch any known vulnerabilities.
- Least Privilege: Run MailCatcher with the lowest privileges necessary. Do not run it as root.
- Containerization: Run MailCatcher in a Docker container to isolate it from the host system. This limits the impact of a successful exploit.
- Security Audits: (Less practical for a small tool like MailCatcher) Consider security audits or penetration testing if MailCatcher is used in a particularly sensitive environment.