CVE-2014-8413 in Asterisk
Summary
by MITRE
The res_pjsip_acl module in Asterisk Open Source 12.x before 12.7.1 and 13.x before 13.0.1 does properly create and load ACLs defined in pjsip.conf at startup, which allows remote attackers to bypass intended PJSIP ACL rules.
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Analysis
by VulDB Data Team • 02/27/2022
The vulnerability identified as CVE-2014-8413 resides within the res_pjsip_acl module of Asterisk Open Source versions 12.x prior to 12.7.1 and 13.x prior to 13.0.1. This issue fundamentally compromises the security posture of affected systems by introducing a critical flaw in the Access Control List (ACL) handling mechanism. The vulnerability manifests during the startup process when the system attempts to create and load ACLs defined in the pjsip.conf configuration file, creating a window of opportunity for malicious actors to exploit the improper implementation of access controls.
The technical flaw stems from inadequate validation and processing of ACL configurations during system initialization. When Asterisk processes the pjsip.conf file to establish network access controls, the res_pjsip_acl module fails to properly validate or enforce the defined ACL rules. This improper handling allows remote attackers to circumvent the intended security restrictions that should prevent unauthorized access to SIP services. The vulnerability represents a classic case of insufficient input validation and access control enforcement, which can be categorized under CWE-284 Access Control Bypass. The flaw essentially creates a scenario where the system's intended security boundaries become ineffective, enabling unauthorized network access that should have been blocked by the configured ACLs.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it fundamentally undermines the trust model of the SIP infrastructure. Remote attackers can exploit this weakness to gain access to services that should be restricted, potentially leading to a range of security incidents including unauthorized calling, denial of service attacks, and even complete system compromise. The vulnerability affects the core communication capabilities of Asterisk-based systems, which are widely deployed in enterprise environments for voice over IP communications. This makes the impact particularly severe as organizations relying on these systems face potential exposure to unauthorized network activities that could compromise sensitive communications and data integrity.
Mitigation strategies for CVE-2014-8413 primarily focus on immediate software updates to patched versions of Asterisk. Organizations should prioritize upgrading to Asterisk 12.7.1 or later versions for the 12.x series, and 13.0.1 or later for the 13.x series to address the root cause of the vulnerability. Additionally, system administrators should implement network-level controls including firewall rules to restrict access to SIP services, particularly to minimize the attack surface. The remediation approach aligns with ATT&CK technique T1071.004 Application Layer Protocol: SIP, as it addresses the exploitation of communication protocols through proper access control implementation. Network segmentation and monitoring should also be enhanced to detect any anomalous behavior that might indicate exploitation attempts, while regular security audits of configuration files can help identify potential misconfigurations that could compound the vulnerability's impact.