CVE-2017-20126 in KB Affiliate Referral Script
Summary
by MITRE • 07/13/2022
A vulnerability was found in KB Affiliate Referral Script 1.0. It has been classified as critical. This affects an unknown part of the file /index.php. The manipulation of the argument username/password with the input 'or''=' leads to sql injection. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 11/11/2022
The vulnerability identified as CVE-2017-20126 represents a critical sql injection flaw in the KB Affiliate Referral Script version 1.0, demonstrating a severe security weakness that exposes the application to remote exploitation. This vulnerability specifically targets the authentication mechanism within the application's index.php file, where improper input validation allows malicious actors to manipulate the username and password parameters through crafted sql payloads. The attack vector is particularly dangerous because it enables remote exploitation without requiring authentication, making it accessible to any attacker with network access to the vulnerable system.
The technical implementation of this vulnerability stems from inadequate parameter sanitization and input validation within the application's database interaction logic. When users submit login credentials through the index.php interface, the script fails to properly escape or validate the username and password inputs before incorporating them into sql queries. The specific payload 'or''=' demonstrates how an attacker can manipulate the sql query structure by injecting additional logical conditions that bypass authentication mechanisms entirely. This type of vulnerability aligns with CWE-89, which categorizes sql injection as a fundamental weakness in data handling and query construction within applications. The flaw exists in the application's core authentication flow where user-supplied data directly influences database query execution without proper sanitization measures.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete control over the affected system's database layer. Remote exploitation allows threat actors to extract sensitive user information, modify database records, and potentially escalate privileges to gain administrative control over the entire application. The disclosure of this exploit to the public significantly increases the risk profile, as it removes the element of technical sophistication required to identify and exploit the vulnerability. Security professionals should consider this weakness in the context of ATT&CK framework's T1190 technique for exploitation of remote services, where the vulnerability can be leveraged for initial access and lateral movement within compromised networks.
Organizations utilizing this specific version of the KB Affiliate Referral Script must implement immediate mitigations to protect against exploitation attempts. The primary remediation strategy involves implementing proper input validation and parameterized queries to prevent sql injection attacks, ensuring that all user-supplied data undergoes rigorous sanitization before database interaction. Additionally, network-level protections such as web application firewalls should be deployed to monitor and block suspicious sql injection patterns targeting the vulnerable index.php endpoint. The vulnerability also highlights the importance of regular security assessments and keeping applications updated with the latest security patches, as this flaw represents a preventable weakness that could have been addressed through proper code review and security testing practices.