CVE-2003-0935 in net-snmp
Summary
by MITRE
Net-SNMP before 5.0.9 allows a user or community to access data in MIB objects, even if that data is not allowed to be viewed.
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Analysis
by VulDB Data Team • 06/26/2019
The vulnerability identified as CVE-2003-0935 represents a significant security flaw in the Net-SNMP implementation that affects versions prior to 5.0.9. This issue resides in the access control mechanisms of the Simple Network Management Protocol implementation, specifically within how the system handles community string validation and permission checking for Management Information Base (MIB) object access. The flaw allows unauthorized users to bypass normal access restrictions and retrieve data from MIB objects that should be protected or restricted based on configured access controls.
This vulnerability stems from inadequate validation of access permissions within the SNMP protocol implementation where community strings are used for authentication and authorization purposes. The technical flaw manifests when the system fails to properly enforce access control lists or access control models that should restrict which users or communities can view specific MIB objects. The issue is particularly concerning because it affects the fundamental security model of SNMP implementations, where community strings serve as the primary means of controlling access to network management information.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential for unauthorized network reconnaissance and monitoring activities. Attackers can exploit this flaw to gain access to sensitive network information that should remain protected, potentially revealing network topology details, device configurations, performance metrics, and other operational data that could be leveraged for further attacks. This vulnerability particularly affects organizations that rely on SNMP for network management and monitoring, as it undermines the security assumptions that network administrators make about access controls.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues in software implementations, and relates to ATT&CK technique T1046 for network service scanning and T1082 for system information discovery. The flaw represents a classic case of privilege escalation through access control bypass, where the system fails to properly validate that the requesting entity has sufficient permissions to access specific network management information. Organizations implementing SNMP-based monitoring solutions must recognize that this vulnerability can be exploited by both internal and external threat actors to gather intelligence about network infrastructure and operations.
The recommended mitigation strategy involves upgrading to Net-SNMP version 5.0.9 or later, which contains the necessary patches to address the access control validation issues. Additionally, network administrators should implement proper SNMP community string management, including using strong, unique community strings, restricting SNMP access to trusted network segments, and implementing network segmentation to limit exposure. The vulnerability also highlights the importance of regular security assessments and patch management processes, particularly for critical network infrastructure components that handle sensitive operational data. Organizations should also consider implementing additional monitoring and logging mechanisms to detect unauthorized SNMP access attempts that could indicate exploitation of this vulnerability.