Incorrect behavior order in Apache Wicket: a file path is validated before the framework appends the attributes that complete it.
org.apache.wicket.request.resource.PackageResource asks the configured package resource guard about a path built from the scope class' package and the file name in the request URL, and then hands that same path to the resource stream locator together with a style, a variation and a locale. Those three attributes are decoded from the name of the first query parameter and never appear in the string the guard was given. org.apache.wicket.core.util.resource.locator.ResourceNameIterator appends them to that path, each preceded by an underscore, in the order variation, style, locale, before the file extension, so the file that is opened is not the file the guard approved.
org.apache.wicket.markup.html.PackageResourceGuard decides whether an HTML file is a component's markup template by looking for a class file of the same name beside it, stripping one underscore-delimited suffix at a time as it goes. HTML is on the default allow list, so that check is the only thing separating a static HTML file, which may be served, from a markup template, which may not. Asked about the name of a template, the guard refuses it correctly. Asked about a shorter name for which no class exists, it accepts, and a style supplied in the URL then completes that name into the markup template of a component class, which is written to the response.
An application is affected if the simple name of any of its component classes contains an underscore and no shorter part of that name is itself a class, such as Report_v2 or Wizard_Step1; an application with no such class name is not affected. No unusual deployment, packaging or configuration is required, and running in deployment rather than development mode does not prevent it. Java naming conventions discourage underscores in class names and no module Wicket ships has one, so no framework markup is exposed; what an application exposes this way is its own. A component whose class name has no underscore is not reachable, and neither is its localized or styled markup, because the guard finds the class file under the base name and refuses the request. The attributes cannot change the file extension and cannot leave the component's package, so nothing beyond HTML files in that package is reachable. Access is read-only, and what is disclosed is developer-authored template content: component structure, developer comments, markup that is rendered only under some conditions, inline script, and the endpoints a template names. No user data, credential or session material is reachable this way. An attacker has to name a class in the target package and the component itself, and Wicket writes fully qualified class names into the URL of every package resource it renders.
This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.
No affected software listed.
A vulnerability database tells you what is broken. Attack surface management tells you where it is running: it discovers your internet-facing assets and flags the ones affected by issues like this one.
What is attack surface management? →A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.