CVE-2020-26934 in phpMyAdmin
Summary
by MITRE • 10/11/2020
phpMyAdmin before 4.9.6 and 5.x before 5.0.3 allows XSS through the transformation feature via a crafted link.
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Analysis
by VulDB Data Team • 11/18/2020
The vulnerability identified as CVE-2020-26934 represents a cross-site scripting flaw within phpMyAdmin that affects versions prior to 4.9.6 and 5.x prior to 5.0.3. This issue specifically exploits the transformation feature of phpMyAdmin, which is designed to provide enhanced data display capabilities by allowing users to apply various transformations to database columns such as converting data to different formats or applying custom functions. The flaw occurs when phpMyAdmin processes crafted links that contain malicious script code within the transformation parameters, enabling attackers to inject arbitrary JavaScript code into the application's response.
The technical implementation of this vulnerability stems from insufficient input validation and output sanitization within the transformation handling mechanism. When phpMyAdmin processes transformation definitions, it fails to properly escape or validate user-supplied parameters that are used to construct dynamic content. This allows an attacker to craft a malicious URL containing script code within the transformation configuration, which gets executed when the victim accesses the affected page. The vulnerability is particularly concerning because it can be exploited through links that appear legitimate, making social engineering attacks more effective. The attack vector typically involves an attacker creating a specially crafted URL that includes malicious JavaScript within the transformation parameters, which are then processed by phpMyAdmin and executed in the victim's browser context.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious websites. An attacker who successfully exploits this vulnerability can potentially gain access to sensitive database information, manipulate user sessions, or use the compromised phpMyAdmin instance as a launching point for further attacks against the underlying database infrastructure. The vulnerability affects both the web interface and the administrative functions of phpMyAdmin, making it particularly dangerous for database administrators who frequently use the application. Given that phpMyAdmin is widely deployed in web applications and database management systems, this vulnerability can impact numerous organizations and increase the attack surface for potential breaches.
Mitigation strategies for CVE-2020-26934 primarily focus on upgrading to the patched versions of phpMyAdmin, specifically version 4.9.6 or later for the 4.x series and version 5.0.3 or later for the 5.x series. Organizations should also implement additional defensive measures such as input validation for all user-supplied data, proper output encoding of dynamic content, and regular security audits of web applications. The vulnerability aligns with CWE-79 which describes cross-site scripting flaws, and can be categorized under ATT&CK technique T1059.007 for scripting languages and T1566 for phishing attacks. Security administrators should also consider implementing web application firewalls, content security policies, and regular monitoring of suspicious user activities to detect potential exploitation attempts. The remediation process should include comprehensive testing of the updated phpMyAdmin installation to ensure that all transformation features function correctly while maintaining security. Organizations with legacy systems should prioritize this update as part of their vulnerability management strategy, given the widespread use of phpMyAdmin in database administration environments and the relatively straightforward nature of the patch deployment process.