CVE-2021-29400 in My SMTP Contact Plugin
Summary
by MITRE • 08/11/2021
A cross-site request forgery (CSRF) vulnerability in the My SMTP Contact v1.1.1 plugin for GetSimple CMS allows remote attackers to change the SMTP settings of the contact forms for the webpages of the CMS after an authenticated admin visits a malicious third-party site.
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Analysis
by VulDB Data Team • 08/16/2021
The CVE-2021-29400 vulnerability represents a critical cross-site request forgery flaw within the My SMTP Contact plugin version 1.1.1 for GetSimple CMS systems. This vulnerability operates through a fundamental weakness in the plugin's authentication and request validation mechanisms, creating an attack vector that can be exploited by remote adversaries. The flaw specifically targets the administrative functionality of contact form SMTP settings, allowing unauthorized modifications to core email configuration parameters that control how contact form submissions are processed and delivered.
The technical implementation of this CSRF vulnerability stems from the absence of proper anti-CSRF token validation within the plugin's configuration update endpoints. When an authenticated administrator user visits a malicious website containing crafted requests, the vulnerable plugin fails to verify the authenticity of the originating request, instead accepting and processing the modification commands as legitimate administrative actions. This occurs because the plugin does not implement proper request origin verification or token-based authentication mechanisms that would prevent unauthorized requests from being executed on behalf of authenticated users.
The operational impact of this vulnerability extends beyond simple configuration changes, as it allows attackers to completely compromise the contact form functionality of affected websites. An attacker could redirect all contact form submissions to malicious email addresses, potentially enabling spamming activities, data exfiltration, or phishing campaigns. The vulnerability also poses significant risks to website integrity and user trust, as unauthorized modifications to email delivery configurations could disrupt legitimate business communications and create opportunities for further attacks. Additionally, this flaw could be leveraged as a stepping stone for more sophisticated attacks, including privilege escalation or lateral movement within compromised systems.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in software applications. The issue also maps to several ATT&CK techniques including T1566 for phishing and T1071 for application layer protocols, demonstrating how CSRF vulnerabilities can serve as initial access vectors for broader attack campaigns. Organizations should prioritize immediate remediation through plugin updates, implementation of web application firewalls, and enforcement of proper CSRF protection mechanisms including the use of anti-CSRF tokens and strict referer header validation. Regular security assessments of third-party plugins and CMS components remain essential for preventing similar vulnerabilities from compromising web application security postures and maintaining the integrity of content management systems.