CVE-2014-6436 in DSL5018EN
Summary
by MITRE
Aztech ADSL DSL5018EN (1T1R), DSL705E, and DSL705EU devices improperly manage sessions, which allows remote attackers to bypass authentication in opportunistic circumstances and execute arbitrary commands with administrator privileges by leveraging an existing web portal login.
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Analysis
by VulDB Data Team • 08/06/2024
The CVE-2014-6436 vulnerability affects Aztech ADSL modems including the DSL5018EN (1T1R), DSL705E, and DSL705EU models, presenting a critical authentication bypass flaw that enables remote attackers to gain administrator-level access to network devices. This vulnerability stems from improper session management within the device's web portal authentication system, creating a pathway for attackers to execute arbitrary commands without proper credentials. The flaw operates under opportunistic conditions, meaning attackers can exploit it when the device is in use, typically when legitimate users are logged into the web interface. The vulnerability specifically targets the session handling mechanisms that should maintain user authentication state and prevent unauthorized access to administrative functions.
The technical implementation of this vulnerability involves a flaw in how the modem's web server manages session tokens and authentication states. When users log into the administrative web portal, the device should establish a secure session that prevents unauthorized access to privileged functions. However, the flawed session management allows attackers to manipulate session identifiers or exploit timing conditions to gain access to the administrative interface without proper authentication. This type of vulnerability falls under CWE-613, which addresses inadequate session management, and represents a classic case of insufficient session handling that violates fundamental security principles for maintaining user authentication states.
The operational impact of this vulnerability is severe as it provides attackers with complete administrative control over the affected modems, enabling them to modify network configurations, change user credentials, install malicious firmware, or redirect traffic through the device. Attackers can leverage this privilege escalation to compromise the entire network infrastructure, as these modems often serve as the primary gateway between internal networks and external internet connections. The opportunistic nature of the exploit means that the vulnerability can be triggered without requiring extensive reconnaissance or specialized tools, making it particularly dangerous for widespread deployment. This aligns with ATT&CK technique T1021.001 for remote services and T1059.007 for command and scripting interpreter, as attackers can execute arbitrary commands and maintain persistent access through the compromised administrative interface.
Mitigation strategies for CVE-2014-6436 should prioritize immediate firmware updates from Aztech, as the vendor likely released patches addressing the session management flaws. Network administrators should implement additional security measures including disabling unnecessary remote administrative access, configuring strong authentication mechanisms, and monitoring for unusual login patterns or command execution attempts. The vulnerability highlights the importance of proper session token generation and validation, requiring devices to implement robust session management protocols that include secure token generation, proper session timeout handling, and protection against session fixation attacks. Organizations should also consider network segmentation to limit the potential impact of such compromises and implement intrusion detection systems capable of identifying anomalous administrative access patterns. The remediation process should include comprehensive network scanning to identify all affected devices and verification of patch installation to ensure complete protection against this class of authentication bypass vulnerability.