CVE-2025-66308

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. This vulnerability is fixed in 1.11.0-beta.1.

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. This vulnerability is fixed in 1.11.0-beta.1.

Summary

A Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector.

Details

Vulnerable Endpoint: POST /admin/config/site
Parameter: data[taxonomies]

The application does not properly validate or sanitize input in the data[taxonomies] field. As a result, an attacker can inject JavaScript code, which is stored in the site configuration and later rendered in the administrative interface or site output, causing automatic execution in the user's browser.

PoC

Payload:

"><script>alert('XSS-PoC')</script>

Steps to Reproduce:

1. Log in to the Grav Admin Panel with sufficient permissions to modify site configuration.

2. Navigate to Configuration > Site.

3. In the Taxonomies Types field (which maps to data[taxonomies]), insert the payload above:

   "><script>alert('XSS-PoC')</script>

4. Save the configuration.

<img width="1897" height="628" alt="Pasted image 20250718195942" src="https://github.com/user-attachments/assets/2035fcaa-34fc-494c-a7ca-7c1e1f34b057" />

5. Go on Pages and click on one of them

<img width="932" height="587" alt="Pasted image 20250718200306" src="https://github.com/user-attachments/assets/3c1995ba-2581-4e27-ae9d-a17e2eeb5b57" />

6. The stored payload is executed immediately in the browser, confirming the Stored XSS vulnerability.

<img width="1204" height="377" alt="Pasted image 20250718200353" src="https://github.com/user-attachments/assets/ad8ea7ea-603f-4b84-aa5a-120de0cb56ce" />

7. The HTTP request submitted during this process contains the vulnerable parameter and payload:

<img width="757" height="675" alt="Pasted image 20250718200445" src="https://github.com/user-attachments/assets/fbbe2b76-00eb-4426-8ddd-5cde2cc65d77" />

Impact

Stored XSS attacks can lead to severe consequences, including:

• Session hijacking: Stealing cookies or authentication tokens to impersonate users

• Credential theft: Harvesting usernames and passwords using malicious scripts

• Malware delivery: Distributing unwanted or harmful code to victims

• Privilege escalation: Compromising administrative users through persistent scripts

• Data manipulation or defacement: Changing or disrupting site content

• Reputation damage: Eroding trust among site users and administrators

Discoverer

Marcelo Queiroz

by CVE-Hunters

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. This vulnerability is fixed in 1.11.0-beta.1.

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. This vulnerability is fixed in 1.11.0-beta.1.

Summary

A Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector.

Details

Vulnerable Endpoint: POST /admin/config/site
Parameter: data[taxonomies]

The application does not properly validate or sanitize input in the data[taxonomies] field. As a result, an attacker can inject JavaScript code, which is stored in the site configuration and later rendered in the administrative interface or site output, causing automatic execution in the user's browser.

PoC

Payload:

"><script>alert('XSS-PoC')</script>

Steps to Reproduce:

1. Log in to the Grav Admin Panel with sufficient permissions to modify site configuration.

2. Navigate to Configuration > Site.

3. In the Taxonomies Types field (which maps to data[taxonomies]), insert the payload above:

   "><script>alert('XSS-PoC')</script>

4. Save the configuration.

<img width="1897" height="628" alt="Pasted image 20250718195942" src="https://github.com/user-attachments/assets/2035fcaa-34fc-494c-a7ca-7c1e1f34b057" />

5. Go on Pages and click on one of them

<img width="932" height="587" alt="Pasted image 20250718200306" src="https://github.com/user-attachments/assets/3c1995ba-2581-4e27-ae9d-a17e2eeb5b57" />

6. The stored payload is executed immediately in the browser, confirming the Stored XSS vulnerability.

<img width="1204" height="377" alt="Pasted image 20250718200353" src="https://github.com/user-attachments/assets/ad8ea7ea-603f-4b84-aa5a-120de0cb56ce" />

7. The HTTP request submitted during this process contains the vulnerable parameter and payload:

<img width="757" height="675" alt="Pasted image 20250718200445" src="https://github.com/user-attachments/assets/fbbe2b76-00eb-4426-8ddd-5cde2cc65d77" />

Impact

Stored XSS attacks can lead to severe consequences, including:

• Session hijacking: Stealing cookies or authentication tokens to impersonate users

• Credential theft: Harvesting usernames and passwords using malicious scripts

• Malware delivery: Distributing unwanted or harmful code to victims

• Privilege escalation: Compromising administrative users through persistent scripts

• Data manipulation or defacement: Changing or disrupting site content

• Reputation damage: Eroding trust among site users and administrators

Discoverer

Marcelo Queiroz

by CVE-Hunters