1. Introduction
The EZPZ One Click Backup Plugin for WordPress ‘cmd’ Parameter Remote Command Execution vulnerability allows a remote attacker to execute arbitrary commands on a vulnerable web server. This poses a critical risk as it could lead to complete system compromise, data theft, or denial of service. Systems running the EZPZ One Click Backup Plugin are affected, particularly those directly exposed to the internet. A successful exploit can result in full confidentiality, integrity and availability loss.
2. Technical Explanation
The vulnerability stems from insufficient input validation within the ezpz-archive-cmd.php script. Specifically, the ‘cmd’ parameter is not properly sanitized before being used to construct a system command. This allows an attacker to inject arbitrary commands into the shell execution process. The CVE associated with this issue is CVE-2014-3114.
- Root cause: Lack of input validation on the ‘cmd’ parameter in
ezpz-archive-cmd.php. - Exploit mechanism: An attacker can send a crafted HTTP request with malicious commands embedded within the ‘cmd’ parameter, leading to arbitrary code execution. For example, an attacker could use a URL like
http://example.com/wp-content/plugins/ezpz-backup/ezpz-archive-cmd.php?cmd=whoamito execute the ‘whoami’ command on the server. - Scope: WordPress installations with the EZPZ One Click Backup Plugin version prior to discontinuation (as of 4/27/2012) are affected.
3. Detection and Assessment
Confirming vulnerability requires checking for the presence of the plugin and potentially attempting a test command execution. Due to the age of this vulnerability, direct scanning may be unreliable.
- Quick checks: Check the WordPress plugins directory (
/wp-content/plugins/) for the ‘ezpz-backup’ folder. - Scanning: Nessus plugin ID 68437 or OpenVAS scanner family “WordPress Plugins” may detect this vulnerability, but results should be verified manually.
- Logs and evidence: Examine web server access logs for requests to
/wp-content/plugins/ezpz-backup/ezpz-archive-cmd.phpwith suspicious ‘cmd’ parameters.
ls /wp-content/plugins/ezpz-backup/ezpz-archive-cmd.php # Check if the file exists.
4. Solution / Remediation Steps
The recommended solution is to uninstall the EZPZ One Click Backup Plugin due to its discontinued development and lack of security updates.
4.1 Preparation
- No services need to be stopped for this process.
4.2 Implementation
- Step 1: Log into your WordPress administration dashboard.
- Step 2: Navigate to ‘Plugins’ in the left-hand menu.
- Step 3: Locate the ‘EZPZ One Click Backup Plugin’.
- Step 4: Deactivate and delete the plugin.
4.3 Config or Code Example
No config or code changes are required; this fix involves removing the vulnerable plugin.
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent similar vulnerabilities. Input validation is crucial for blocking malicious data, and least privilege limits the impact of successful exploits.
- Practice 1: Implement strict input validation on all user-supplied data to prevent command injection attacks.
- Practice 2: Apply the principle of least privilege to web server users, limiting their access to only necessary resources.
4.5 Automation (Optional)
Automating plugin removal is possible using WP-CLI if available.
wp plugin uninstall ezpz-backup --yes # Uninstall the plugin without prompting.
5. Verification / Validation
Verify the fix by confirming the plugin has been removed and attempting to access its files or functionality.
- Post-fix check: Verify that the ‘ezpz-backup’ folder no longer exists in
/wp-content/plugins/. - Re-test: Attempt to access
/wp-content/plugins/ezpz-backup/ezpz-archive-cmd.php; it should return a 404 error.
ls /wp-content/plugins/ # Confirm 'ezpz-backup' is not listed.
6. Preventive Measures and Monitoring
Regularly update all WordPress plugins and themes, and consider using a security scanner to identify potentially vulnerable components.
- Baselines: Maintain a current list of approved WordPress plugins and themes.
- Pipelines: Integrate SAST or SCA tools into your CI/CD pipeline to scan for known vulnerabilities in dependencies.
- Asset and patch process: Implement a regular schedule for reviewing and updating WordPress core, plugins, and themes.
7. Risks, Side Effects, and Roll Back
- Risk or side effect 1: Loss of existing backups created by the EZPZ One Click Backup Plugin.
- Roll back: Restore your WordPress database and files from the pre-uninstall backup if necessary.
8. References and Resources
Refer to official advisories for accurate information regarding this vulnerability.
- Vendor advisory or bulletin: No current vendor advisory exists due to discontinued development.
- NVD or CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-3114
- Product or platform documentation relevant to the fix: https://www.openwall.com/lists/oss-security/2014/05/01/11