CVE-2005-1247 in Nsure Audit
Summary
by MITRE
webadmin.exe in Novell Nsure Audit 1.0.1 allows remote attackers to cause a denial of service via malformed ASN.1 packets in corrupt client certificates to an SSL server, as demonstrated using an exploit for the OpenSSL ASN.1 parsing vulnerability.
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Analysis
by VulDB Data Team • 07/21/2019
The vulnerability identified as CVE-2005-1247 affects the webadmin.exe component within Novell Nsure Audit version 1.0.1, presenting a significant security risk that enables remote attackers to execute denial of service attacks against SSL servers. This flaw specifically targets the ASN.1 parsing functionality within the software's certificate handling mechanisms, creating an avenue for malicious actors to disrupt legitimate service operations. The vulnerability manifests when malformed ASN.1 packets are transmitted through corrupt client certificates, which the software fails to properly validate or process, leading to service disruption.
The technical implementation of this vulnerability stems from inadequate input validation within the ASN.1 parsing routines of the webadmin.exe application. When the system receives client certificates containing malformed ASN.1 structures, the parsing logic becomes overwhelmed or enters an undefined state, causing the SSL server to crash or become unresponsive. This represents a classic example of an improper input validation flaw that can be categorized under CWE-20, which addresses improper input validation in software systems. The vulnerability leverages the broader OpenSSL ASN.1 parsing vulnerability, demonstrating how flaws in underlying cryptographic libraries can be exploited to compromise higher-level applications that depend on these components.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by attackers to systematically deny access to critical SSL services that organizations rely upon for secure communications. The remote nature of the attack means that adversaries can target systems from anywhere on the network without requiring physical access or local privileges, making the vulnerability particularly dangerous in enterprise environments where SSL services are commonly deployed. This type of attack aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how cryptographic vulnerabilities can be weaponized to compromise availability of network services.
Organizations affected by this vulnerability should implement immediate mitigations including updating to patched versions of Novell Nsure Audit, applying firewall rules to restrict access to SSL ports, and implementing monitoring for suspicious certificate validation patterns. The vulnerability also highlights the importance of proper certificate validation procedures and input sanitization in security-critical applications, reinforcing the need for comprehensive security testing of cryptographic components. System administrators should consider implementing intrusion detection systems to monitor for exploitation attempts and establish incident response procedures to quickly address potential exploitation of this vulnerability.