CVE-2015-1591 in Kamailio
Summary
by MITRE
The kamailio build in kamailio before 4.2.0-2 process allows local users to gain privileges.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2015-1591 affects the kamailio SIP server software version 4.2.0-2 and earlier, presenting a critical privilege escalation risk for local users. This issue stems from improper privilege handling within the software's build process, specifically related to how the application manages user permissions during installation and execution phases. The flaw exists in the software's ability to maintain proper access controls when transitioning between different user contexts, creating an avenue for malicious local users to elevate their privileges.
The technical implementation of this vulnerability involves a flaw in the kamailio build system that fails to properly drop elevated privileges after performing certain operations. When the software executes with root or administrator privileges during the build process, it does not adequately restrict these elevated permissions during subsequent operations. This misconfiguration allows local attackers to exploit the privilege escalation mechanism by manipulating the build environment or execution context. The vulnerability manifests when the application performs operations that require elevated privileges but does not properly sanitize the execution environment or user context before proceeding with privilege-restricted operations.
From an operational perspective, this vulnerability poses significant risk to systems running affected versions of kamailio, particularly in environments where the software is installed with elevated privileges or where local users might have access to the build environment. Attackers could leverage this flaw to gain root access on systems running kamailio, potentially leading to complete system compromise. The impact extends beyond individual system compromise as the vulnerability affects the software's core privilege management mechanisms, making it difficult to contain the attack vector to a single service or application. Organizations using kamailio for VoIP services, SIP routing, or communication infrastructure are particularly vulnerable since these systems often require elevated privileges to function properly.
The vulnerability aligns with CWE-276, which addresses improper privileges, and represents a classic example of privilege escalation through improper access control. From an attack framework perspective, this vulnerability maps to the privilege escalation techniques described in the MITRE ATT&CK framework under the privilege escalation tactics. The flaw demonstrates how build-time privilege handling can create persistent security weaknesses that affect runtime operations. Security practitioners should note that this vulnerability is particularly dangerous because it occurs during the software installation or build phase, meaning that even if the system appears secure during normal operations, the underlying privilege escalation mechanism remains exploitable.
Mitigation strategies for CVE-2015-1591 primarily involve upgrading to kamailio version 4.2.0-2 or later, which contains the necessary fixes to properly manage privilege transitions. Organizations should also implement strict access controls on build environments and ensure that software installation occurs with minimal privileges. Additional measures include monitoring for unauthorized privilege escalation attempts and implementing proper privilege separation in the deployment environment. System administrators should conduct thorough vulnerability assessments of their kamailio installations and ensure that all systems are updated to versions that address this specific privilege escalation flaw. Regular security audits of build processes and privilege management mechanisms are essential to prevent similar vulnerabilities from emerging in other software components.