CVE-2023-25579 : Exploit Details and Defense Strategies

This CVE details a directory traversal vulnerability in Nextcloud server that can lead to path traversal, potentially allowing attackers to overwrite data from other users with crafted paths.

Understanding CVE-2023-25579

This vulnerability in Nextcloud server affects versions prior to 23.0.12, 24.0.8, and 25.0.2. The issue arises from improper limitation of a pathname to a restricted directory, leading to path traversal.

What is CVE-2023-25579?

CVE-2023-25579 is a directory traversal vulnerability in Nextcloud server that allows attackers to create paths outside of their designated space, potentially overwriting data from other users using crafted paths.

The Impact of CVE-2023-25579

The impact of this vulnerability is rated as medium severity, with low confidentiality, integrity, and availability impacts. Attack complexity is high, but privileges required are low. The vulnerability can be exploited remotely without user interaction.

Technical Details of CVE-2023-25579

This vulnerability in Nextcloud server arises from the

OC\\Files\\Node\\Folder::getFullPath()

function incorrectly validating and normalizing strings, allowing for the creation of paths outside of the intended space.

Vulnerability Description

The vulnerable function

OC\\Files\\Node\\Folder::getFullPath()

is used in

newFile()

and

newFolder()

operations, enabling attackers to overwrite data from other users with manipulated paths.

Affected Systems and Versions

The affected versions of Nextcloud server include versions prior to 23.0.12, 24.0.8, and 25.0.2. Users operating on these versions are at risk of exploitation through the directory traversal vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating crafted paths to traverse directories improperly, leading to unauthorized access and potential data overwriting.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-25579, users and administrators are advised to take immediate action to secure their Nextcloud servers and data.

Immediate Steps to Take

Upgrade Nextcloud server to versions 25.0.2, 24.0.8, or 23.0.12 to patch the vulnerability.
Regularly monitor for security advisories and updates from Nextcloud to stay informed about potential vulnerabilities.

Long-Term Security Practices

Implement proper access controls and permissions to restrict users from accessing files and directories they are not authorized to.
Conduct regular security audits and assessments to identify and address vulnerabilities proactively.

Patching and Updates

Nextcloud has released patches in versions 25.0.2, 24.0.8, and 23.0.12 to fix the directory traversal vulnerability. It is crucial for users to apply these updates promptly to protect their systems from exploitation.