CVE-2003-0372 in Nessus
Summary
by MITRE
Signed integer vulnerability in libnasl in Nessus before 2.0.6 allows local users with plugin upload privileges to cause a denial of service (core dump) and possibly execute arbitrary code by causing a negative argument to be provided to the insstr function as used in a NASL script.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability described in CVE-2003-0372 represents a critical signed integer overflow flaw within the Network Security Scanner library known as libnasl which is integral to the Nessus vulnerability assessment tool. This issue specifically affects Nessus versions prior to 2.0.6 and stems from improper handling of integer values within the insstr function, a core component used in NASL script execution. The vulnerability manifests when local users who possess plugin upload privileges can manipulate input parameters to trigger unexpected behavior in the software's memory management systems.
The technical exploitation of this vulnerability occurs through a specific code path where a negative integer value is passed as an argument to the insstr function, which is designed to handle string insertion operations within NASL scripts. When the signed integer overflow occurs, it creates conditions that can lead to memory corruption, potentially causing the application to crash with a core dump or in more severe cases, allowing for arbitrary code execution within the context of the Nessus process. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which is a well-documented weakness in software systems where arithmetic operations produce results that exceed the maximum value that can be represented by the target data type.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it represents a potential privilege escalation vector for malicious users who already have plugin upload capabilities. In environments where Nessus is deployed for security testing, this vulnerability could be exploited to gain unauthorized access to systems or compromise the integrity of security assessments. The attack requires local access with specific privileges but the potential consequences are significant, as it could allow an attacker to execute arbitrary code with the privileges of the Nessus service account, potentially leading to complete system compromise.
Mitigation strategies for this vulnerability require immediate patching of Nessus installations to version 2.0.6 or later, which contains the necessary fixes for the integer overflow condition. Organizations should also implement strict access controls to limit plugin upload privileges to only trusted administrators and consider implementing additional monitoring for unusual memory usage patterns or core dump generation. The vulnerability demonstrates the importance of proper input validation and integer handling in security tools, as these systems often run with elevated privileges and are critical to maintaining organizational security posture. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and execution of arbitrary code, making it a significant concern for security operations centers that rely on Nessus for vulnerability assessment activities.