Overview of Web Security Scanner (original) (raw)

Web Security Scanner identifies security vulnerabilities and misconfigurations in your App Engine, Google Kubernetes Engine (GKE), and Compute Engine web applications. It crawls your application, following all links within the scope of your starting URLs, and attempts to exercise as many user inputs and event handlers as possible. Web Security Scanner only supports public URLs and IPs that aren't behind a firewall.

Web Security Scanner supports the App Engine standard environment and App Engine flexible environments, Compute Engine instances, and GKE resources.

Web Security Scanner is designed to complement your existing secure design and development processes. To avoid distracting you with false positives, Web Security Scanner errs on the side of under reporting and doesn't display low confidence alerts. It does not replace a manual security review, and it does not guarantee that your application is free from security flaws.

Findings categorized as misconfigurations represent issues that can be resolved through customer action by updating configurations. Although these findings are important for improving security posture, they are distinct from vulnerabilities, which represent actively exploitable weaknesses. You can view these misconfigurations on the Findings page of Security Command Center. For more information, seeWeb Security Scanner misconfiguration findings.

Scan types

Web Security Scannerprovides managed and custom web vulnerability scanning for public App Engine, GKE, and Compute Engine serviced web applications.

Managed scans

Web Security Scanner managed scans are configured and managed by Security Command Center. Managed scans automatically run once each week to detect and scan public web endpoints. These scans don't use authentication and they send GET-only requests so they don't submit any forms on live websites.

Managed scans run separately from custom scans.

If Security Command Center is activated at theorganization level, you can use managed scans to centrally manage basic web application vulnerability detection for projects in your organization, without having to involve individual project teams. When findings are discovered, you can work with those teams to set up more comprehensive custom scans.

When you enable Web Security Scanner as a service, managed scan findings are automatically available in the Security Command Center Vulnerabilities page and related reports. For information about how to enable Web Security Scanner managed scans, seeConfigure Security Command Center services.

Managed scans support only applications that use the default port, which is 80 for HTTP connections and 443 for HTTPS connections. If your application uses a non-default port, do a custom scan instead.

Custom scans

Web Security Scanner custom scans provide granular information about application vulnerability findings, like outdated libraries, cross-site scripting, or use of mixed content.

You define custom scans at the project level.

Custom scan findings are available in Security Command Center after you complete the guide toset up Web Security Scanner custom scans.

Scan findings

This section describes Web Security Scanner finding types and relevant compliance standards.

Detectors and compliance

Web Security Scanner supports categories in theOWASP Top Ten, a document that ranks and provides remediation guidance for the top 10 most critical web application security risks, as determined by the Open Web Application Security Project (OWASP).

The compliance mapping is included for reference and is not provided or reviewed by the OWASP Foundation. It's only intended for you to monitor for compliance controls violations. The mappings are not provided for use as the basis of, or as a substitute for, the audit, certification, or report of compliance of your products or services with any regulatory or industry benchmarks or standards.

For more information about compliance, seeAssess and report security benchmark compliance.

Finding types

Web Security Scanner custom and managed scans identify the following finding types. In the Standard tier, Web Security Scanner supports custom scans of deployed applications with public URLs and IPs that aren't behind a firewall.

Usage caveats

The IAM roles for Security Command Center can be granted at the organization, folder, or project level. Your ability to view, edit, create, or update findings, assets, and security sources depends on the level for which you are granted access. To learn more about Security Command Center roles, see Access control.

Other important things to be aware of when using Web Security Scanner:

• Because Web Security Scanner is undergoing continual improvements, a future scan might report issues that are not reported by the current scan.
• Some features or sections of your application might not be tested.
• Web Security Scanner attempts to activate every control and input it finds.
• Web Security Scanner only supports websites using IPv4. Websites using IPv6 are not scanned.
• If you expose state-changing actions for which your test account has permission, Web Security Scanner is likely to activate them. This might lead to undesirable results.
• Web Security Scanner has a limit of 15 scans per project. Because scans are run concurrently, users who reach this limit are advised to add multiple starting URLs per scan, or to add scans to different projects that have not yet reached the limit.

Who can run a security scan?

For information about the Identity and Access Management (IAM) roles that are available for Web Security Scanner, seeAccess control.

How much time is required for a security scan?

The security scan does not execute immediately. It is queued and then executes later, possibly hours later depending on system load. After the scan starts to execute, the time it takes will depend on the size of your application. A scan of a large application with many URLs can take several hours, or even days. If a scan has not completed within 20 days, the scan is automatically stopped, and all crawl results and findings found during the scan will be visible as the scan result.

Target restrictions

Web Security Scanner has filters in place that restrict scan targets to the specific App Engine instance for which the scan is created. Entering URLs for a different App Engine project or an outside domain will result in an error message.

Scans for Compute Engine and GKE are restricted to domains that map to static external IP addresses reserved for the same project and static external IP addresses that belong to the same project. For instructions on reserving IP addresses for projects, see the following links:

• Compute Engine:Reserving a static external IP address
• GKE:Configuring domain names with static IP addresses

App Engine does not provide a way to map static IP addresses to an application. However, you can use Cloud Load Balancing and serverless network endpoint groups toreserve a static IP address for your load balancer, which then directs traffic to your application. For information about pricing, see All networking pricing.

Within your project, the Web Security Scanner automatically attempts to avoid logout URLs and other generic locations that may adversely affect a scan. However, to be sure, you can use the scan settings to manuallyexclude URLs.

Validation

Scan configurations are validated when they are created and before each scan. Web Security Scanner checks Security Command Center settings and your application's authentication credentials to ensure scans are configured correctly and can log into your application successfully. Configuration parameters, including maximum scan speed, are also checked to ensure they are within supported ranges.

You must resolve errors before a scan is created or updated. Applications that are changed after initial configuration may produce errors during scans. For example, if a domain no longer points to an IP address owned by the project, the resource is not scanned and an error is reported on the scan configuration page.

Best practices

Because Web Security Scanner populates fields, pushes buttons, clicks links, and performs other user actions, you should use it with caution, particularly if you are scanning production resources. Web Security Scanner could potentially activate features that change the state of your data or system, with undesirable results.

For example:

• In a blog application that allows public comments, Web Security Scanner might post test strings as comments on all your blog articles.
• In an email sign-up page, Web Security Scanner might generate large numbers of test emails.

Following are some techniques that you can use, separately or in combination, to avoid unwanted outcomes:

1. Run scans in a test environment. Set up a test environment by creating a separate App Engine project and loading your application and data there. If you use the Google Cloud CLI, you can specify the target project as a command-line option when you upload your app.
2. Use a test account. Create a user account that doesn't have access to sensitive data or harmful operations, and use it when scanning your app. Many applications present a special workflow during a user's first-time login, like accepting terms and creating a profile. Because of the different workflow, a test account for an initial user can have different scan results than an established user account. It's best to scan with an account that is in the normal user state, after the first-time flow is complete.
3. Block individual user interface elements that you do not want activated by applying the CSS class inq-no-click. Event handlers that are attached to this element aren't activated during crawling and testing, regardless of whether they are inline JavaScript, or attached using addEventListener, or attached by setting the appropriate event handler property.
4. Use backup data. Consider making a backup of your data before scanning.
5. Excluded URLs. You can specify URL patterns that won't be crawled or tested. For information on syntax, seeExcluding URLs.

Before you scan, carefully audit your application for any feature that might affect data, users, or systems beyond the scope of your scan.

What's next

• Get started with theWeb Security Scanner.