CVE-2013-3433 in Unified Communications Manager
Summary
by MITRE
Untrusted search path vulnerability in Cisco Unified Communications Manager (CUCM) 7.1(x) through 9.1(1a) allows local users to gain privileges by leveraging unspecified file-permission and environment-variable issues for privileged programs, aka Bug ID CSCui02276.
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Analysis
by VulDB Data Team • 12/22/2024
The vulnerability identified as CVE-2013-3433 represents a critical untrusted search path issue affecting Cisco Unified Communications Manager versions 7.1 through 9.1(1a). This flaw resides within the privilege escalation mechanisms of the communication platform, creating a pathway for local attackers to elevate their system privileges. The vulnerability stems from improper handling of environment variables and file permissions within privileged programs, specifically impacting the manner in which the system resolves executable paths during program execution. According to the Cisco bug ID CSCui02276, the issue manifests when the system's search path is manipulated to include directories with insufficient access controls, allowing malicious code injection at critical execution points. The vulnerability operates under CWE-426, which classifies it as an "Untrusted Search Path" weakness, where the system fails to properly validate or sanitize the search path used by privileged applications.
The technical exploitation of this vulnerability requires a local attacker to leverage the compromised environment variable handling within Cisco Unified Communications Manager processes. When privileged programs execute, they traverse search paths that may contain attacker-controlled directories due to inadequate permission controls. This creates a scenario where a malicious actor can place a specially crafted executable in a directory that gets searched before legitimate system directories, causing the privileged program to execute the attacker's code with elevated privileges. The flaw essentially allows for arbitrary code execution within the context of the privileged process, potentially enabling complete system compromise. Attackers can exploit this by manipulating the PATH environment variable or by creating symbolic links in directories that are searched before system directories, as documented in various ATT&CK techniques related to privilege escalation through environment manipulation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can lead to complete system compromise of Cisco Unified Communications Manager installations. Once successfully exploited, attackers can gain unauthorized access to voice communication systems, potentially enabling eavesdropping, call interception, and modification of communication flows. The vulnerability affects organizations relying on Cisco's unified communications infrastructure, which typically includes voice gateways, IP phones, and communication servers. The implications include potential disruption of business communications, data exfiltration through voice channels, and unauthorized access to sensitive communication networks. Organizations with multiple CUCM installations across different versions may face widespread compromise, as the vulnerability exists across a broad range of supported releases. The attack vector is particularly concerning because it requires only local access, making it accessible to insiders or attackers who have gained initial foothold through other means.
Mitigation strategies for CVE-2013-3433 should focus on addressing the underlying environment variable and file permission issues within the Cisco Unified Communications Manager implementation. Organizations should immediately apply Cisco's security patches and updates released for affected versions, which typically include fixes for the untrusted search path handling. System administrators should conduct thorough audits of environment variable configurations, particularly the PATH variable, to ensure that attacker-controlled directories are not included in the search path for privileged programs. Implementing proper file permission controls and directory access restrictions can prevent unauthorized code placement in critical system directories. Additionally, organizations should consider implementing application whitelisting policies to restrict which executables can run with elevated privileges. Network segmentation and monitoring solutions should be deployed to detect anomalous execution patterns that may indicate exploitation attempts. The remediation process should also include regular security assessments of the communication infrastructure to identify similar vulnerabilities in other system components, as this type of issue often indicates broader security configuration weaknesses that require comprehensive addressing.