CVE-2025-23388: Stack-Based Buffer Overflow Vulnerability in SUSE Rancher

Overview

In the realm of cybersecurity, spotting vulnerabilities and patching them up is crucial for maintaining the integrity of a system. This article focuses on the CVE-2025-23388 vulnerability, a stack-based buffer overflow flaw found in SUSE Rancher. The systems affected are those running rancher versions from 2.8.0 to 2.8.13, from 2.9.0 to 2.9.7, and from 2.10.0 to 2.10.3.
This vulnerability is of particular importance due to its potential to cause a denial of service attack. If successfully exploited, this flaw could lead to system compromise or data leakage, posing a significant threat to data integrity and system stability.

Vulnerability Summary

CVE ID: CVE-2025-23388
Severity: High (CVSS Score: 8.2)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Denial of service, potential system compromise, and data leakage

Affected Products

Product | Affected Versions

SUSE Rancher | 2.8.0 to 2.8.13
SUSE Rancher | 2.9.0 to 2.9.7
SUSE Rancher | 2.10.0 to 2.10.3

How the Exploit Works

The exploit operates by overloading the buffer storage in the stack memory space. The attacker sends more data than the buffer can handle, causing it to overflow. This overflow can corrupt data, crash the system, or allow the execution of malicious code leading to full system compromise.

Conceptual Example Code

An exploit could potentially overload the buffer by sending a large amount of data in a single request. While the actual malicious code will vary depending on the specific nature of the vulnerability and the attacker’s intent, a conceptual example may look something like this:

POST /vulnerable/endpoint HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"data": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
}

In this example, the `data` field is filled with a far larger amount of data than the system is prepared to handle, leading to a buffer overflow.

Mitigation Guidance

To protect your systems from this vulnerability, it is recommended to apply the vendor patch as soon as possible. In the scenario where the patch cannot be immediately applied, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary mitigation. These systems can help detect and block malicious attempts to exploit the vulnerability, providing an additional layer of protection for your systems.