CVE-2024-24720 in PBX
Summary
by MITRE • 02/27/2024
An issue was discovered on Innovaphone PBX before 14r1 devices. It provides different responses to incoming requests in a way that reveals information to an attacker.
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Analysis
by VulDB Data Team • 08/14/2024
The vulnerability identified as CVE-2024-24720 affects Innovaphone PBX devices running firmware versions prior to 14r1, representing a significant information disclosure weakness that could enable attackers to gain insights into the system's internal state and configuration. This issue manifests through the device's inconsistent response handling mechanism when processing incoming network requests, creating a potential attack surface that violates fundamental security principles of information hiding and system integrity. The flaw essentially allows an unauthenticated attacker to perform reconnaissance activities by observing variations in system responses to malformed or specially crafted requests.
The technical implementation of this vulnerability stems from the PBX device's response handling logic that fails to maintain consistent behavior across different request scenarios. When processing incoming SIP or other protocol requests, the device provides different response codes, error messages, or timing characteristics depending on whether the request targets a valid or invalid endpoint, or whether it contains specific malicious patterns. This inconsistent response behavior directly violates the principle of consistent error handling that should prevent attackers from inferring system state information through response analysis. The vulnerability falls under the CWE-200 category of Information Exposure, specifically related to information leakage through inconsistent responses, and aligns with ATT&CK technique T1212 for Exploitation for Credential Access through information gathering.
From an operational impact perspective, this vulnerability enables attackers to perform passive reconnaissance without requiring authentication, potentially revealing sensitive information such as valid user accounts, system configurations, network topology details, or software version information. The disclosure could facilitate subsequent attacks including credential brute forcing, privilege escalation attempts, or targeted exploitation of other vulnerabilities within the system. Attackers could leverage this information to craft more effective attacks against the PBX infrastructure, potentially compromising voice communications, disrupting business operations, or gaining unauthorized access to the internal network. The vulnerability's impact is particularly concerning for organizations that rely on Innovaphone PBX systems for critical communication infrastructure, as it provides attackers with valuable intelligence that could be used to plan more sophisticated attacks.
Organizations should immediately upgrade their Innovaphone PBX devices to firmware version 14r1 or later to remediate this vulnerability, as the update includes proper response handling mechanisms that ensure consistent behavior regardless of request content. Network administrators should also implement monitoring solutions to detect unusual patterns of incoming requests that might indicate reconnaissance activities targeting this specific vulnerability. Additional mitigations include implementing network segmentation to limit access to PBX systems, deploying intrusion detection systems that can identify suspicious request patterns, and conducting regular security assessments to identify similar information disclosure vulnerabilities. The remediation process should also include reviewing and updating firewall rules to restrict unnecessary access to PBX services, while ensuring that any security measures implemented do not disrupt legitimate business communications.