CVE-2015-0842: An Inside View on Yubiserver SQL Injection Vulnerability

Overview

In the realm of cybersecurity, few threats are as potentially damaging as SQL injection attacks. One such vulnerability, CVE-2015-0842, affects versions of yubiserver before 0.6. Yubiserver is a software package that many organizations use for authentication purposes. As such, the threat posed by this vulnerability is of significant concern.
The issue opens doors to unauthorized access, data leakage, and in worst-case scenarios, total system compromise. SQL injection vulnerabilities like this one are a favorite tool of cybercriminals, because they provide an opportunity to bypass authentication processes and gain access to sensitive data.

Vulnerability Summary

CVE ID: CVE-2015-0842
Severity: Critical (9.8/10.0)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise, data leakage

Affected Products

Product | Affected Versions

Yubiserver | Versions before 0.6

How the Exploit Works

The exploit works by abusing the SQL injection vulnerability present in the yubiserver software. By crafting malicious SQL queries, an attacker can manipulate the software’s database to bypass the authentication process. This can potentially allow an attacker to gain unauthorized access to the system and its sensitive data.

Conceptual Example Code

Here’s a conceptual example of how the vulnerability might be exploited. This could be a sample HTTP request with a malicious payload:

GET /auth?user=admin&pass=’ OR ‘1’=’1 HTTP/1.1
Host: target.example.com

In this example, the malicious payload is the SQL statement `’ OR ‘1’=’1`, which always evaluates to true and hence, bypasses the authentication.

Prevention and Mitigation

The most effective way to prevent exploitation of this vulnerability is to apply the vendor patch, which addresses the underlying SQL injection issue. Users of affected versions of yubiserver are therefore strongly advised to upgrade to version 0.6 or later as soon as possible.
In cases where immediate patching is not feasible, deploying a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can offer temporary mitigation. These systems can be configured to detect and block SQL injection attacks, thus reducing the risk of exploitation.
It’s also good practice to follow secure coding practices to prevent such vulnerabilities from existing in the first place. This includes using parameterized queries or prepared statements, which can effectively mitigate the risk of SQL injection attacks.
In conclusion, the CVE-2015-0842 vulnerability represents a significant threat, but one that can be effectively managed through timely patching and good security practices.