CVE-1999-0312 in HP-UX
Summary
by MITRE
hp ypbind allows attackers with root privileges to modify nis data.
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Analysis
by VulDB Data Team • 04/03/2025
The vulnerability identified as CVE-1999-0312 affects the hp ypbind service, which is part of the Network Information Service NIS implementation on HP-UX systems. This flaw represents a critical security weakness that enables attackers who have already compromised root privileges on a system to manipulate NIS data through the ypbind daemon. The vulnerability stems from inadequate access controls within the ypbind service that processes NIS requests and updates. When an attacker possesses root access, they can exploit this vulnerability to modify NIS maps and data structures, potentially compromising the integrity of the entire NIS infrastructure. This represents a significant escalation of privileges within the NIS ecosystem, as it allows for unauthorized modification of user accounts, group memberships, and other critical network information managed through NIS.
The technical implementation of this vulnerability resides in the ypbind daemon's handling of NIS update requests and its insufficient validation of incoming data modifications. The flaw allows for direct manipulation of NIS data structures through the ypbind service, bypassing normal access controls that should prevent unauthorized modifications. This vulnerability operates at the system level where NIS data is synchronized across networked systems, making it particularly dangerous for environments that rely heavily on centralized user and configuration management. The attack vector specifically targets the ypbind service which is responsible for binding to NIS servers and maintaining synchronization of NIS maps. This vulnerability aligns with CWE-284 Access Control Issues, specifically focusing on insufficient access control mechanisms within network services. The flaw demonstrates poor privilege separation and inadequate input validation in network daemon implementations.
The operational impact of this vulnerability extends beyond simple data modification capabilities, as it can lead to complete compromise of the NIS infrastructure and subsequent network-wide consequences. An attacker with root access can modify NIS maps to create backdoor accounts, alter user permissions, or redirect network services to malicious endpoints. The vulnerability undermines the fundamental trust model of NIS systems where data integrity is critical for maintaining secure network operations. Organizations relying on NIS for user authentication and network configuration management face severe risks, as this vulnerability can enable persistent access to network resources and facilitate lateral movement within the network. The impact is particularly severe in environments where NIS is used for centralized authentication, as it can lead to complete compromise of user accounts and network access controls. This vulnerability also aligns with ATT&CK technique T1548.001 for Privilege Escalation through root access exploitation.
Mitigation strategies for CVE-1999-0312 require immediate implementation of system hardening measures and proper access control enforcement. Organizations should ensure that ypbind services operate with minimal required privileges and implement proper input validation for all NIS update requests. The recommended approach includes disabling unnecessary NIS services, implementing network segmentation to isolate NIS servers, and ensuring that NIS data is protected through proper access controls and encryption. System administrators should also implement monitoring and alerting for unauthorized NIS data modifications, as well as regular integrity checks of NIS maps. Additionally, organizations should consider migrating away from NIS to more modern authentication and directory services such as LDAP or Kerberos, which provide better security controls and are less susceptible to this class of vulnerability. The fix requires proper implementation of access control lists and validation mechanisms within the ypbind service to prevent unauthorized modifications even when root privileges are compromised. This vulnerability highlights the importance of defense-in-depth strategies and proper privilege management in network services, as it demonstrates how a single flaw in a system daemon can enable widespread compromise of network infrastructure.