How to remediate – Web Application Tests Settings

1. Introduction

Web Application Tests Settings relate to the configuration of HTTP audit options used for web application security testing. This script itself doesn’t perform tests, but controls how other scripts check websites for common weaknesses like cross-site scripting and SQL injection in CGI programs. A misconfiguration could mean tests are ineffective or overly broad. Impact on confidentiality is possible if vulnerabilities go undetected; integrity is at risk from successful attacks; availability may be affected by denial of service resulting from exploitation.

2. Technical Explanation

The vulnerability lies in the settings applied to web application test scripts, not a flaw within a specific product. Exploitation occurs when these settings are either too permissive (allowing tests to miss vulnerabilities) or too restrictive (preventing effective testing). There is no CVE associated with this configuration issue itself. An attacker could exploit an improperly configured system by submitting malicious input that bypasses the tests and compromises the web application. Affected systems include any using CGI scripts and employing a web application test suite governed by these settings.

• Root cause: Incorrectly configured HTTP audit options for web application testing.
• Exploit mechanism: An attacker crafts an input designed to bypass the configured tests, potentially leading to cross-site scripting or SQL injection. For example, a test might not be checking for specific characters used in SQL injection attacks if the settings are too narrow.
• Scope: Web servers using CGI scripts and any web application testing framework relying on these configuration options.

3. Detection and Assessment

Confirming whether systems are vulnerable involves reviewing the current test settings. A quick check is to list the configured options, while a thorough method requires examining each option’s impact.

• Quick checks: Review the configuration file used by the web application tests. The location varies depending on the testing framework.
• Scanning: There are no specific signature IDs for this configuration issue; however, some web vulnerability scanners may flag overly permissive settings during a general scan. These should be treated as examples only.
• Logs and evidence: Examine test logs for skipped tests or warnings related to configuration issues. Log file locations depend on the testing framework.

# Example command placeholder:
# There is no specific command to check this, review config files directly.

4. Solution / Remediation Steps

Fixing this issue involves carefully reviewing and adjusting the web application test settings to ensure comprehensive coverage without being overly restrictive.

4.1 Preparation

• Ensure you have a clear understanding of the testing framework’s documentation and available options. A roll back plan is to restore the backed-up configuration file.
• Changes should be made during a scheduled maintenance window with appropriate approval from IT security or application owners.

4.2 Implementation

1. Step 1: Review each HTTP audit option in the configuration file.
2. Step 2: Ensure options are enabled to detect common vulnerabilities like cross-site scripting, SQL injection, and command injection.
3. Step 3: Adjust settings to balance thoroughness with performance; avoid overly broad rules that generate false positives.
4. Step 4: Save the updated configuration file.

4.3 Config or Code Example

Before

# Example config - restrictive settings
xss_check = false
sql_injection_check = false
command_injection_check = false

After

# Example config - more comprehensive settings
xss_check = true
sql_injection_check = true
command_injection_check = true
file_inclusion_check = true

4.4 Security Practices Relevant to This Vulnerability

Practices that directly address this vulnerability type include input validation and secure defaults. Least privilege can reduce the impact if a web application is exploited.

• Practice 1: Input validation helps prevent malicious data from reaching the web application, reducing the risk of exploitation.
• Practice 2: Secure defaults ensure that tests are configured with reasonable protection out-of-the-box, minimizing the chance of misconfiguration.

4.5 Automation (Optional)

# Example PowerShell script to update config file (use with caution!)
# $configFile = "C:pathtoconfig.ini"
# $newConfigContent = "[Settings]`nXss_check = true`nSql_injection_check = true"
# Set-Content -Path $configFile -Value $newConfigContent -Encoding UTF8

5. Verification / Validation

Confirming the fix involves re-running tests and verifying that they now detect potential vulnerabilities. A smoke test should ensure core application functionality remains intact.

• Post-fix check: Review the configuration file to confirm settings have been updated as expected.
• Re-test: Re-run web application tests and verify that previously skipped tests are now executed without errors.
• Smoke test: Test key user actions such as logging in, submitting forms, and browsing core pages to ensure functionality is unaffected.
• Monitoring: Monitor test logs for any new warnings or errors related to the updated configuration.

# Example command and expected output (after applying changes)
# cat /path/to/config.ini
# [Settings]
# Xss_check = true
# Sql_injection_check = true

6. Preventive Measures and Monitoring

Update security baselines to include recommended test settings. Incorporate checks in CI pipelines to prevent misconfigurations during deployment. Implement a regular patch or config review cycle that fits the risk profile of the application.

• Baselines: Update your security baseline with recommended HTTP audit options for web application testing, referencing CIS controls if applicable.
• Pipelines: Add static analysis checks to CI pipelines to validate configuration files against a known good standard.
• Asset and patch process: Implement a monthly review of test configurations to ensure they remain effective and aligned with current security best practices.

7. Risks, Side Effects, and Roll Back

Risks include false positives or performance impacts from overly aggressive testing. Roll back involves restoring the backed-up configuration file.

• Risk or side effect 1: Overly broad test rules may generate false positives, requiring investigation and potentially impacting application performance.
• Risk or side effect 2: Incorrect settings could still allow certain vulnerabilities to slip through undetected.
• Roll back:
  1. Stop any active tests.
  2. Restore the backed-up configuration file.
  3. Restart the testing framework.

8. References and Resources

• Vendor advisory or bulletin: Consult the documentation for your specific web application testing framework.
• NVD or CVE entry: This configuration issue does not have a dedicated NVD or CVE entry.
• Product or platform documentation relevant to the fix: Refer to the documentation provided by your web server and CGI script provider.