1. Introduction
IBM WebSphere Portal is affected by an information disclosure vulnerability (PI27710) that allows a remote attacker to determine if files exist on the system based on web server error codes. This could allow attackers to map out sensitive file structures, potentially leading to further attacks. Systems running IBM WebSphere Portal are at risk. A successful exploit may lead to limited information disclosure.
2. Technical Explanation
The vulnerability occurs because the version of IBM WebSphere Portal installed on a remote host does not properly handle error codes returned by the web server when attempting to access files. An attacker can send requests for both existing and non-existing files, observing differences in the error responses to identify file presence. This is tracked as CVE-2014-4821.
- Root cause: The web application does not mask or sanitize internal error codes that reveal file existence.
- Exploit mechanism: An attacker sends HTTP requests for known files and then for unknown files, comparing the server responses to determine if a file exists. For example, an attacker might request
/existing_file.txtand/nonexistent_file.txtand compare the resulting error codes. - Scope: IBM WebSphere Portal versions are affected.
3. Detection and Assessment
You can confirm if a system is vulnerable by checking the installed version of IBM WebSphere Portal and testing the web server’s response to requests for existing and non-existing files.
- Quick checks: Check the WebSphere Portal version via the administrative console.
- Scanning: Nessus plugin 70755 can detect this vulnerability. This is an example only.
- Logs and evidence: Examine web server access logs for requests to files, looking for patterns in error codes that indicate file existence disclosure.
# No command available for quick check - use the administrative console.4. Solution / Remediation Steps
Apply Interim Fix PI27710 to address this vulnerability. Follow these steps carefully.
4.1 Preparation
- Ensure you have sufficient disk space for the update files and rollback is to restore from the backup/snapshot taken earlier.
- A change window may be required, depending on your environment. Approval from a system owner might be needed.
4.2 Implementation
- Step 1: Download Interim Fix PI27710 from IBM’s support site (see References).
- Step 2: Apply the fix using the WebSphere Portal Installation Manager or the
installcommand-line tool, following IBM’s instructions.
4.3 Config or Code Example
No configuration change is required; this vulnerability is fixed by applying a patch.
Before
# No config change needed - apply the patch.After
# No config change needed - apply the patch.4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this type of vulnerability.
- Practice 1: Patch management is essential for addressing known vulnerabilities like this one promptly.
- Practice 2: Input validation can prevent attackers from crafting malicious requests that exploit weaknesses in the application logic.
4.5 Automation (Optional)
No automation script provided, as patch installation varies significantly by environment.
# No automation script available.5. Verification / Validation
- Post-fix check: Verify the Interim Fix PI27710 has been installed via the WebSphere Portal Installation Manager or command line interface.
- Re-test: Repeat the test from Section 3, observing that error responses no longer reveal file existence.
- Monitoring: Monitor web server access logs for unusual requests or patterns of errors.
# No command available - use the administrative console to verify patch installation.6. Preventive Measures and Monitoring
Implement security baselines and regular patching to prevent similar vulnerabilities.
- Baselines: Update your WebSphere Portal security baseline to include this fix and future patches.
- Pipelines: Consider incorporating SAST or DAST tools into your CI/CD pipeline to identify potential vulnerabilities early in the development process.
- Asset and patch process: Establish a regular patch review cycle for all critical systems, including WebSphere Portal.
7. Risks, Side Effects, and Roll Back
Applying Interim Fix PI27710 carries minimal risk but could potentially cause compatibility issues with custom applications or configurations.
- Risk or side effect 2: Temporary service interruption during restart – schedule the update during a maintenance window.
- Roll back: Restore from the backup/snapshot taken prior to applying the fix if any issues arise.
8. References and Resources
- Vendor advisory or bulletin: https://www-304.ibm.com/support/docview.wss?uid=swg21684651
- NVD or CVE entry: CVE-2014-4821
- Product or platform documentation relevant to the fix: IBM WebSphere Portal documentation on applying Interim Fixes.