Overview
CVE-2025-66553 is a medium-severity vulnerability affecting the Nextcloud Tables application. This vulnerability allows authenticated users to potentially view metadata of columns in other tables within the application by manipulating the numeric ID in a request. This exposure could lead to information disclosure and potentially aid in further exploitation. The vulnerability has been patched in versions 0.8.7 and 0.9.4 of the Tables application.
Technical Details
The vulnerability stems from insufficient access control checks within the Nextcloud Tables application. Specifically, the application fails to properly validate the user’s authorization when retrieving column metadata. By modifying the numeric ID associated with a table column in an HTTP request, an authenticated user can bypass the intended access restrictions and access metadata related to columns in other tables, even if they do not have explicit permission to view those tables. The vulnerability is caused by directly using the provided table column ID without verifying if the current user has access to the specified table. This allows an attacker to iterate through table IDs and retrieve associated column metadata.
CVSS Analysis
The Common Vulnerability Scoring System (CVSS) score for CVE-2025-66553 is 4.3 (Medium). The CVSS vector is: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): Low (L)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): Low (L)
- Integrity (I): None (N)
- Availability (A): None (N)
This score indicates that the vulnerability is exploitable remotely with low complexity, requires low privileges (an authenticated user), and does not require any user interaction. The impact is limited to partial information disclosure (Low Confidentiality).
Possible Impact
Successful exploitation of CVE-2025-66553 could allow an attacker to:
- Gain knowledge of table structures and column names within the Nextcloud Tables application.
- Potentially identify sensitive data fields based on column names and metadata.
- Use the gathered information to aid in further attacks, such as SQL injection or data exfiltration, although this vulnerability alone does not directly enable these attacks.
Mitigation and Patch Steps
To mitigate the risk associated with CVE-2025-66553, it is crucial to update your Nextcloud Tables application to version 0.8.7 or 0.9.4, or a later version. These versions contain the necessary fixes to address the insufficient access control checks. To update:
- Log in to your Nextcloud instance as an administrator.
- Navigate to the Apps section.
- Search for the “Tables” app.
- If an update is available, click the “Update” button.
- Verify that the Tables app version is 0.8.7 or 0.9.4 or higher after the update.
After updating, it is recommended to review your application logs for any suspicious activity related to unauthorized metadata access.
