CVE-2026-72578 in FreePBX
Summary
by MITRE • 08/10/2026
A cross-site request forgery (CSRF) vulnerability in FreePBX Framework 17.0 allows an unauthenticated remote attacker to perform administrative actions on behalf of an authenticated administrator. The /admin/ajax.php dispatcher in amp_conf/htdocs/admin/libraries/BMO/Ajax.class.php does not implement CSRF tokens; its only protection is a Referer header check that is bypassed when the request is sent without a Referer header or from a same-site context, enabling attackers to trigger admin operations by luring an administrator to a malicious page.
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Analysis
by VulDB Data Team • 08/10/2026
This cross site request forgery vulnerability exists within the FreePBX Framework version 17.0 and represents a critical security flaw that undermines the integrity of administrative operations. The vulnerability stems from the absence of proper CSRF token implementation in the ajax.php dispatcher located at amp_conf/htdocs/admin/libraries/BMO/Ajax.class.php. The system relies solely on a Referer header validation mechanism which provides insufficient protection against malicious attacks. This design flaw creates a pathway for unauthenticated remote attackers to execute administrative actions without proper authorization, potentially leading to complete system compromise.
The technical implementation of this vulnerability demonstrates a fundamental misunderstanding of web security principles and violates established security standards such as CWE-352, which specifically addresses cross-site request forgery vulnerabilities. The flawed protection mechanism only checks the Referer header, an approach that has been widely deprecated in modern security practices due to its susceptibility to bypass techniques. When requests are sent without a Referer header or when attacks originate from same-site contexts, the validation becomes ineffective, allowing attackers to craft malicious pages that can trigger administrative functions simply by luring administrators into visiting these pages.
The operational impact of this vulnerability extends far beyond simple privilege escalation as it provides attackers with complete control over the affected FreePBX system. Administrators who visit malicious web pages could unknowingly execute commands such as user creation, configuration changes, system modifications, or even complete system compromise. This vulnerability affects the core administrative functionality of FreePBX and represents a serious threat to VoIP infrastructure security, particularly in enterprise environments where these systems manage critical communication networks. The attack vector is particularly dangerous because it requires minimal user interaction beyond visiting a malicious page, making it highly effective for social engineering campaigns.
Mitigation strategies should include immediate implementation of proper CSRF token mechanisms throughout the application framework, specifically within the Ajax.class.php module. Organizations should implement anti-CSRF tokens that are generated per session and validated on each request, ensuring that requests cannot be forged without knowledge of the valid token. The existing Referer header validation should be completely removed or supplemented with additional security measures such as SameSite cookies, origin validation, or custom headers that provide more robust protection against cross-site attacks. The implementation should align with established security frameworks and best practices outlined in both CWE guidelines and ATT&CK tactics for web application exploitation, particularly focusing on privilege escalation and defense evasion techniques that attackers might employ through CSRF vulnerabilities.
Organizations utilizing FreePBX Framework 17.0 must prioritize immediate patching or workaround implementation to address this vulnerability. The absence of proper CSRF protection in administrative interfaces represents a critical gap in the security posture that requires urgent attention. Security teams should conduct comprehensive assessments of their FreePBX installations to ensure no similar vulnerabilities exist within other components, as this flaw demonstrates a pattern of inadequate input validation and authorization mechanisms in the framework's core modules.