CVE-2002-0545 in Aironet AP340
Summary
by MITRE
Cisco Aironet before 11.21 with Telnet enabled allows remote attackers to cause a denial of service (reboot) via a series of login attempts with invalid usernames and passwords.
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Analysis
by VulDB Data Team • 05/13/2019
The vulnerability described in CVE-2002-0545 represents a significant security flaw in Cisco Aironet wireless access point devices running firmware versions prior to 11.21. This issue specifically affects the authentication mechanism of these network devices when Telnet service is enabled, creating a pathway for remote attackers to disrupt network operations through deliberate denial of service attacks. The vulnerability stems from the device's inadequate handling of repeated failed authentication attempts, which can be exploited to trigger unintended system behavior.
The technical implementation of this vulnerability involves the device's failure to properly manage authentication failure states during Telnet sessions. When attackers repeatedly attempt to log in with invalid credentials, the system does not implement appropriate rate limiting or account lockout mechanisms that would normally prevent such brute force attempts. Instead, the device processes each failed login attempt in a manner that eventually leads to system instability and automatic reboot. This behavior is classified as a weakness in the authentication system, aligning with CWE-307 which addresses inadequate account lockout mechanisms and CWE-400 which covers improper handling of exceptional conditions.
From an operational perspective, this vulnerability poses a serious threat to network availability and business continuity. Attackers can exploit this weakness to repeatedly reboot network infrastructure devices, causing service disruption for legitimate users and potentially creating security gaps during the reboot process. The impact extends beyond simple service interruption as it can affect wireless network coverage, authentication services, and overall network management capabilities. Network administrators face the challenge of maintaining service availability while dealing with the potential for repeated attacks that can render network infrastructure unusable until manual intervention occurs.
The exploitation of this vulnerability aligns with techniques documented in the MITRE ATT&CK framework under the T1499 category for network denial of service attacks. The attack pattern involves leveraging weak authentication controls to create persistent service disruption, which is particularly concerning for wireless networks that often serve as critical infrastructure components. Organizations using affected Cisco Aironet devices must consider the broader implications of such vulnerabilities, as they can be used as stepping stones for more complex attacks or as part of coordinated campaigns targeting network availability.
Mitigation strategies for this vulnerability primarily focus on firmware upgrades to version 11.21 or later, which contain the necessary patches to address the authentication handling issues. Network administrators should disable Telnet services entirely and implement SSH as a more secure alternative for remote management access. Additionally, implementing network access control lists and rate limiting mechanisms can help reduce the effectiveness of brute force attacks against authentication services. The vulnerability also highlights the importance of regular security assessments and timely patch management processes, as it demonstrates how legacy authentication mechanisms can create persistent security weaknesses in network infrastructure devices.