CVE-2003-0982 in ACNS
Summary
by MITRE
Buffer overflow in the authentication module for Cisco ACNS 4.x before 4.2.11, and 5.x before 5.0.5, allows remote attackers to execute arbitrary code via a long password.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/22/2025
The vulnerability described in CVE-2003-0982 represents a critical buffer overflow flaw within Cisco's Application Control Engine Network Security (ACNS) software authentication module. This issue affects versions 4.x prior to 4.2.11 and 5.x prior to 5.0.5, creating a significant security weakness that remote attackers can exploit to gain unauthorized system access. The flaw specifically manifests when the system processes authentication requests containing excessively long password inputs, demonstrating a classic buffer overflow condition where insufficient input validation allows memory corruption.
The technical implementation of this vulnerability stems from inadequate bounds checking within the authentication module's password handling routine. When a malicious user submits a password exceeding the allocated buffer size, the system fails to properly validate the input length before copying it into memory. This condition creates a writable buffer that extends beyond its allocated boundaries, allowing attackers to overwrite adjacent memory locations including return addresses and control data. The vulnerability aligns with CWE-121, which describes classic stack-based buffer overflow conditions, and represents a fundamental flaw in input sanitization and memory management practices.
From an operational perspective, this vulnerability presents severe implications for organizations relying on Cisco ACNS solutions for network security management. Remote exploitation enables attackers to execute arbitrary code with the privileges of the affected service, potentially leading to complete system compromise and unauthorized network access. The attack vector requires no authentication initially, making it particularly dangerous as it can be exploited from external networks without prior credentials. This characteristic places the vulnerability in the ATT&CK framework under T1210 - Exploitation of Remote Services, and T1068 - Exploitation for Privilege Escalation, highlighting its potential for lateral movement and persistent access within compromised networks.
Organizations must implement immediate mitigation strategies to address this vulnerability, beginning with applying the vendor-provided security patches that update the authentication module to versions 4.2.11 and 5.0.5 respectively. Network segmentation and access control measures should be strengthened to limit exposure of affected systems to untrusted networks. Additionally, implementing intrusion detection systems capable of identifying malformed authentication requests and monitoring for unusual network behavior can provide early warning of exploitation attempts. Security teams should also conduct comprehensive vulnerability assessments to identify all instances of the affected software versions and establish monitoring procedures for similar buffer overflow conditions in legacy network infrastructure components. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and implementing proper input validation controls in network security applications to prevent exploitation of fundamental memory management flaws.