CVE-2000-1054 in Secure Access Control Server
Summary
by MITRE
Buffer overflow in CSAdmin module in CiscoSecure ACS Server 2.4(2) and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a large packet.
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Analysis
by VulDB Data Team • 10/11/2025
The vulnerability described in CVE-2000-1054 represents a critical buffer overflow condition within the CSAdmin module of CiscoSecure Access Control Server versions 2.4(2) and earlier. This flaw exists in the server-side processing of network packets and demonstrates a fundamental weakness in input validation and memory management practices that were prevalent in network security appliances during the late 1990s and early 2000s. The buffer overflow vulnerability specifically affects the administrative interface component responsible for handling remote management communications, making it a particularly dangerous flaw for network administrators who rely on remote access capabilities.
The technical implementation of this vulnerability stems from inadequate bounds checking within the CSAdmin module when processing incoming network packets. When a remote attacker sends a specially crafted packet containing an excessive amount of data, the application fails to properly validate the packet size before copying data into fixed-size buffers. This classic buffer overflow scenario occurs because the application does not enforce proper input length limits, allowing attackers to overwrite adjacent memory locations in the process heap. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though the specific implementation likely involves heap-based memory corruption due to the nature of network packet processing in server applications. The flaw essentially creates a situation where attacker-controlled data can overwrite critical program variables, return addresses, or function pointers, leading to unpredictable behavior and potential code execution.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling remote code execution, which represents a severe compromise of network security infrastructure. When exploited, the buffer overflow can cause the CiscoSecure ACS Server to crash and restart, resulting in denial of service for legitimate network access control functions. However, the more concerning aspect is that under certain conditions, attackers might be able to manipulate the overwritten memory locations to inject and execute arbitrary code on the target system. This would allow unauthorized individuals to gain administrative privileges within the access control server, potentially compromising the entire network authentication infrastructure. The vulnerability affects organizations that rely on CiscoSecure ACS for network access control, making it particularly dangerous for enterprise environments where network security is paramount. According to ATT&CK framework, this vulnerability maps to T1203 - Exploitation for Client Execution and T1499 - Endpoint Termination, as it enables both remote code execution and system disruption.
Mitigation strategies for CVE-2000-1054 require immediate action from affected organizations to prevent exploitation of this vulnerability. The most effective approach involves applying the official Cisco security patches and updates that address the buffer overflow in the CSAdmin module. Organizations should also implement network segmentation and access controls to limit exposure of the vulnerable server to untrusted networks. Network administrators should consider implementing intrusion detection systems that can identify and block malformed packets attempting to exploit this vulnerability. Additionally, disabling unnecessary administrative services and ports when not required provides an additional layer of defense. The vulnerability highlights the importance of regular security updates and proper input validation in network security appliances, as recommended by security standards such as NIST SP 800-125 and ISO/IEC 27001. Organizations should also conduct regular vulnerability assessments and penetration testing to identify similar buffer overflow conditions in other network security components, as this class of vulnerability was particularly common in network infrastructure software during this era of rapid development and limited security awareness.