CVE-2025-66303

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

DOS on the admin panel

Severity Rating: Medium

Vector: Denial Of Service

CVE: XXX

CWE: 400 - Uncontrolled Resource Consumption

CVSS Score: 4.9

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Analysis

A Denial of Service (DoS) vulnerability has been identified in the application related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations.

The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression

Proof of Concept

1. Change the value of scheduled_at parameter to ' as shown in the following figures at the http://127.0.0.1/admin/tools endpoint, and observe the response in the second figure: Figure: Http request on tool endpoint Figure: Http response on tool endpoint

2. When trying to access the admin panel, the panel is broken as shown in the following figure. Additionally, the value change is reflected in the backup.yaml file, as shown in the second figure: Figure: Error message view Figure: Backup.yaml file

Workarounds

No workaround is currently known

Timeline

2024-07-24 Issue identified

2024-09-27 Vendor contacted

About X41 D-Sec GmbH

X41 is an expert provider for application security services. Having extensive industry experience and expertise in the area of information security, a strong core security team of world class security experts enables X41 to perform premium security services.

Fields of expertise in the area of application security are security centered code reviews, binary reverse engineering and vulnerability discovery. Custom research and IT security consulting and support services are core competencies of X41.

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

DOS on the admin panel

Severity Rating: Medium

Vector: Denial Of Service

CVE: XXX

CWE: 400 - Uncontrolled Resource Consumption

CVSS Score: 4.9

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Analysis

A Denial of Service (DoS) vulnerability has been identified in the application related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations.

The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression

Proof of Concept

1. Change the value of scheduled_at parameter to ' as shown in the following figures at the http://127.0.0.1/admin/tools endpoint, and observe the response in the second figure: Figure: Http request on tool endpoint Figure: Http response on tool endpoint

2. When trying to access the admin panel, the panel is broken as shown in the following figure. Additionally, the value change is reflected in the backup.yaml file, as shown in the second figure: Figure: Error message view Figure: Backup.yaml file

Workarounds

No workaround is currently known

Timeline

2024-07-24 Issue identified

2024-09-27 Vendor contacted

About X41 D-Sec GmbH

X41 is an expert provider for application security services. Having extensive industry experience and expertise in the area of information security, a strong core security team of world class security experts enables X41 to perform premium security services.

Fields of expertise in the area of application security are security centered code reviews, binary reverse engineering and vulnerability discovery. Custom research and IT security consulting and support services are core competencies of X41.