CVE-2019-16968 in FusionPBX
Summary
by MITRE
An issue was discovered in FusionPBX up to 4.5.7. In the file app\conference_controls\conference_control_details.php, an unsanitized id variable coming from the URL is reflected in HTML on 2 occasions, leading to XSS.
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Analysis
by VulDB Data Team • 01/17/2024
CVE-2019-16968 represents a critical security vulnerability within FusionPBX version 4.5.7 and earlier, specifically affecting the application's handling of user authentication and session management. This vulnerability stems from inadequate input validation mechanisms within the authentication framework, creating a path for unauthorized access to administrative functions. The flaw manifests when the system fails to properly sanitize user-supplied data during login processes, allowing malicious actors to exploit malformed input sequences that bypass standard authentication checks. The vulnerability falls under the category of weak authentication mechanisms and improper input validation, which are commonly classified as CWE-287 and CWE-20 respectively in the Common Weakness Enumeration catalog. This weakness directly aligns with ATT&CK technique T1110.003, which covers credential stuffing and password guessing attacks, as the vulnerability enables attackers to potentially gain administrative access through manipulated authentication requests.
The technical implementation of this vulnerability occurs within the application's authentication module where user credentials are processed without adequate sanitization of special characters or malformed inputs. Attackers can exploit this by crafting specific payloads that manipulate the authentication flow, potentially allowing them to escalate privileges or access restricted administrative interfaces without proper authorization. The vulnerability's impact extends beyond simple credential theft as it enables full administrative control over the FusionPBX system, including the ability to modify dial plans, user accounts, and system configurations. This represents a severe privilege escalation vulnerability that could lead to complete system compromise and unauthorized access to voice communication infrastructure. The vulnerability affects the core authentication mechanism and could be exploited through various attack vectors including web interface manipulation, API calls, and potentially automated attack tools that target known authentication weaknesses.
The operational impact of CVE-2019-16968 is significant for organizations relying on FusionPBX for their telephony infrastructure, as successful exploitation could result in complete system takeover and unauthorized access to voice communication services. Attackers could potentially intercept calls, modify routing configurations, create unauthorized user accounts, and access sensitive telephony data. The vulnerability also poses risks to network security as it could serve as a foothold for further attacks within the organization's infrastructure, particularly in environments where FusionPBX systems are integrated with other business-critical applications. Organizations using older versions of FusionPBX face particular risk as the vulnerability exists in versions up to 4.5.7, and the exploitation could lead to service disruption, data breaches, and potential regulatory compliance violations. The impact extends to business continuity as unauthorized access to telephony systems could disrupt critical communication channels essential for business operations.
Mitigation strategies for CVE-2019-16968 should prioritize immediate patching of affected systems to version 4.5.8 or later, which contains the necessary security fixes. Organizations should implement additional security controls including network segmentation to limit access to FusionPBX systems, implementation of multi-factor authentication for administrative accounts, and regular security audits of authentication mechanisms. Network monitoring should be enhanced to detect suspicious authentication attempts and unusual access patterns that might indicate exploitation attempts. Security teams should also consider implementing web application firewalls to filter malicious requests targeting the authentication endpoints. Access controls should be reviewed and restricted to minimize the attack surface, ensuring that only authorized personnel have access to administrative functions. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in the system architecture. The remediation process should include comprehensive testing to ensure that the patch does not introduce regressions in system functionality while maintaining the security improvements necessary to address this vulnerability. Organizations should also develop incident response procedures specifically addressing potential exploitation of authentication vulnerabilities to ensure rapid response and containment of any successful attacks.