CVE-1999-0956 in NeXTstep
Summary
by MITRE
the next netinfo _writers property allows local users to gain root privileges or conduct a denial of service.
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Analysis
by VulDB Data Team • 04/17/2026
The vulnerability described in CVE-1999-0956 resides within the Next NetInfo system, specifically targeting the _writers property mechanism that controls access permissions for network information services. This flaw represents a classic privilege escalation vulnerability that allows local users to exploit weaknesses in the system's authorization model to gain root-level access or disrupt system operations. The vulnerability is particularly concerning as it operates at the core of network information service management, where proper access controls are essential for maintaining system integrity and security.
The technical implementation of this vulnerability stems from improper handling of the _writers property within the Next NetInfo framework. When local users interact with this property, the system fails to properly validate or restrict access permissions, creating a pathway for unauthorized privilege elevation. This flaw operates under CWE-264, which categorizes improper access control issues, specifically targeting the system's ability to enforce proper authorization boundaries. The vulnerability is classified as a local privilege escalation vector because it requires only local system access to exploit, making it particularly dangerous in environments where multiple users share system resources.
The operational impact of this vulnerability extends beyond simple privilege escalation to include potential denial of service scenarios that can severely disrupt network operations. When exploited, local users can either assume root privileges to execute arbitrary commands with full system access or manipulate the _writers property to prevent legitimate network operations from functioning correctly. This dual nature makes the vulnerability particularly dangerous as attackers can choose between gaining administrative control or simply disrupting services. The attack surface is broadened by the fact that NetInfo services are commonly used in networked environments, making this vulnerability relevant across multiple deployment scenarios.
Mitigation strategies for CVE-1999-0956 should focus on implementing proper access control measures and system hardening techniques. Organizations should ensure that all NetInfo services are properly configured with restrictive permissions and that the _writers property is properly validated before any modifications are accepted. The implementation of principle of least privilege should be enforced, limiting local user access to network information services. Additionally, regular system audits should verify that access controls are properly configured and that no unauthorized modifications have been made to the NetInfo system. This vulnerability demonstrates the critical importance of proper authorization controls in system design, as highlighted by ATT&CK technique T1068 which covers privilege escalation through local system exploitation. The vulnerability also underscores the need for proper input validation and access control implementation, aligning with security best practices outlined in various industry standards including NIST SP 800-53 and ISO 27001 frameworks.