CVE-2023-25162 : Vulnerability Insights and Analysis

This CVE involves a vulnerability in Nextcloud Server that allows for Server-Side Request Forgery (SSRF) through a bypass of IP filters due to lax checking on IPs.

Understanding CVE-2023-25162

This vulnerability affects the Nextcloud Server software, a self-hosted productivity platform, exposing it to SSRF attacks due to inadequate IP filter checks.

What is CVE-2023-25162?

Nextcloud Server versions prior to 24.0.8 and 23.0.12, as well as Nextcloud Enterprise Server versions prior to 24.0.8 and 23.0.12, are susceptible to SSRF attacks. Attackers can exploit this flaw to bypass IP filters using alphanumeric payloads, potentially leading to unauthorized access to critical metadata, especially on AWS-hosted servers.

The Impact of CVE-2023-25162

The impact of this vulnerability is rated as MEDIUM with a CVSS score of 5.3. While it poses a relatively low attack complexity and does not directly impact availability or integrity, it can compromise the confidentiality of data stored on affected servers.

Technical Details of CVE-2023-25162

This section discusses the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability in Nextcloud Server allows for SSRF attacks by exploiting lax IP filter checks, enabling attackers to manipulate payloads to bypass filters and gain unauthorized access to sensitive data.

Affected Systems and Versions

Nextcloud Server versions prior to 24.0.8 and 23.0.12
Nextcloud Enterprise Server versions prior to 24.0.8 and 23.0.12

Exploitation Mechanism

Attackers can send crafted requests containing specific alphanumeric payloads to trick the server into bypassing IP filters, thus carrying out SSRF attacks successfully.

Mitigation and Prevention

To address CVE-2023-25162, it is crucial to take immediate steps to secure affected systems and implement long-term security practices.

Immediate Steps to Take

Update Nextcloud Server to versions 24.0.8 or 23.0.12, or later.
Implement network restrictions and access controls to mitigate the risk of SSRF attacks.

Long-Term Security Practices

Regularly apply security patches and updates to the Nextcloud Server software.
Conduct security assessments and penetration testing to identify and address potential vulnerabilities proactively.

Patching and Updates

Nextcloud Server versions 24.0.8 and 23.0.12, as well as Nextcloud Enterprise Server versions 24.0.8 and 23.0.12, contain patches for CVE-2023-25162. Ensure timely installation of these updates to safeguard your systems against SSRF exploits.