CVE-2014-2128 in ASA
Summary
by MITRE
The SSL VPN implementation in Cisco Adaptive Security Appliance (ASA) Software 8.2 before 8.2(5.47, 8.3 before 8.3(2.40), 8.4 before 8.4(7.3), 8.6 before 8.6(1.13), 9.0 before 9.0(3.8), and 9.1 before 9.1(3.2) allows remote attackers to bypass authentication via (1) a crafted cookie value within modified HTTP POST data or (2) a crafted URL, aka Bug ID CSCua85555.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability described in CVE-2014-2128 represents a critical authentication bypass flaw within Cisco Adaptive Security Appliance SSL VPN implementations. This weakness affects multiple versions of ASA software across several release branches, creating a widespread security risk for organizations relying on these network security devices. The vulnerability specifically targets the authentication mechanisms that protect access to corporate networks through SSL VPN connections, potentially allowing unauthorized users to gain access to protected resources without proper credentials.
The technical implementation flaw stems from insufficient validation of authentication tokens within the SSL VPN subsystem. Attackers can exploit this weakness by crafting malicious HTTP POST requests containing manipulated cookie values or by constructing specially formatted URLs that bypass the normal authentication flow. This vulnerability operates at the application layer of the network stack, specifically targeting the web interface components that handle SSL VPN session management and user authentication. The flaw allows adversaries to manipulate session state information in a way that the system incorrectly interprets as valid authentication, effectively granting access to the SSL VPN portal without proper user credentials.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it can enable attackers to establish persistent network presence within corporate environments. Once authenticated, malicious actors can potentially escalate privileges, access sensitive data, and use the compromised SSL VPN connection as a launching point for further attacks against internal network resources. This vulnerability particularly affects organizations that rely heavily on SSL VPN for remote access, as it undermines the fundamental security principle of requiring valid authentication before granting network access. The attack vectors are relatively simple to implement, requiring only basic web application exploitation techniques and making this vulnerability particularly dangerous in environments where security monitoring may not detect abnormal authentication patterns.
Organizations affected by this vulnerability should immediately implement the vendor-provided security patches and updates for their ASA software versions. The remediation process requires careful planning and execution to ensure that network availability is maintained while addressing the authentication bypass issue. Security teams should also implement enhanced monitoring of SSL VPN authentication logs to detect potential exploitation attempts and establish network segmentation controls to limit the lateral movement capabilities of compromised sessions. This vulnerability aligns with CWE-287, which addresses improper authentication issues, and represents a significant concern from the ATT&CK framework perspective under the credential access and privilege escalation tactics. The vulnerability demonstrates how insufficient input validation and session management can create persistent security weaknesses that require both immediate patching and ongoing monitoring to prevent exploitation attempts.