CVE-2023-2802 in Ultimate Addons for Contact Form 7 Plugin
Summary
by MITRE • 08/14/2023
The Ultimate Addons for Contact Form 7 WordPress plugin before 3.1.29 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
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Analysis
by VulDB Data Team • 09/09/2023
The vulnerability identified as CVE-2023-2802 affects the Ultimate Addons for Contact Form 7 WordPress plugin, specifically versions prior to 3.1.29. This issue represents a critical security flaw that undermines the plugin's ability to properly handle user input within its administrative settings. The vulnerability stems from insufficient sanitization and escaping of data within the plugin's configuration parameters, creating a persistent security risk that can be exploited by attackers with administrative privileges.
The technical flaw manifests in the plugin's failure to adequately sanitize user-supplied input when processing settings within its admin interface. This oversight creates a stored cross-site scripting vulnerability that allows attackers to inject malicious scripts into the plugin's configuration settings. The vulnerability is particularly concerning because it can be exploited even when the WordPress multisite environment has restricted the unfiltered_html capability, which typically prevents users without elevated privileges from injecting raw HTML content. This means that administrators who should be protected by these security measures can still be compromised through this vulnerability.
The operational impact of this vulnerability extends beyond simple script injection as it provides attackers with a persistent vector for executing malicious code within the context of the WordPress administrator's session. The stored nature of the XSS vulnerability means that once an attacker successfully injects malicious scripts, these payloads will execute every time the affected settings are loaded or displayed, potentially allowing for session hijacking, privilege escalation, or data exfiltration. The vulnerability affects high-privilege users specifically, making it particularly dangerous as it targets administrators who have the ability to modify core plugin functionality and access sensitive data.
The security implications of this vulnerability align with CWE-79, which categorizes cross-site scripting flaws as weaknesses in input validation and output escaping. Additionally, this vulnerability can be mapped to ATT&CK technique T1059.001 for command and scripting interpreter, as it provides a pathway for attackers to execute malicious scripts within the browser context of privileged users. The vulnerability also relates to T1548.001 for abuse of privileges, as it allows for potential privilege escalation through the exploitation of administrative settings. Organizations using this plugin in multisite environments face increased risk as the vulnerability can be exploited to compromise entire network ecosystems where administrative access is required to manage multiple sites.
Mitigation strategies should focus on immediate plugin updates to version 3.1.29 or later, which contain the necessary sanitization and escaping fixes. Administrators should also implement additional security measures including regular security audits of installed plugins, monitoring for unauthorized configuration changes, and ensuring that only necessary users have administrative privileges. Network segmentation and monitoring solutions should be employed to detect potential exploitation attempts, while regular security assessments should verify that all plugins maintain proper input validation and output escaping mechanisms. Organizations should also consider implementing web application firewalls and content security policies to provide additional layers of protection against similar vulnerabilities.