CVE-1999-0208 in AIX
Summary
by MITRE
rpc.ypupdated (nis) allows remote users to execute arbitrary commands.
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Analysis
by VulDB Data Team • 12/07/2024
The vulnerability identified as CVE-1999-0208 affects the rpc.ypupdated service within the Network Information Service NIS system, representing a critical remote code execution flaw that has significant implications for network security. This vulnerability specifically targets the NIS server component responsible for maintaining and updating network-wide information databases, making it a prime target for attackers seeking to compromise entire network infrastructures. The issue stems from improper input validation within the ypupdated daemon, which processes requests from remote clients without adequate sanitization of command parameters.
The technical flaw resides in the way rpc.ypupdated handles incoming remote procedure calls, particularly when processing update requests from clients. When remote users submit commands through the NIS update mechanism, the system fails to properly validate or sanitize the input data before executing any operations. This allows malicious actors to inject arbitrary commands that get executed with the privileges of the ypupdated service, typically running with root-level permissions. The vulnerability operates at the protocol level, leveraging the inherent trust relationships within NIS systems where legitimate administrative operations are processed without sufficient security checks.
The operational impact of this vulnerability extends far beyond individual system compromise, as it enables attackers to gain complete control over NIS-managed networks. Once exploited, the vulnerability allows adversaries to execute any command on the affected system, potentially leading to full network infiltration, data exfiltration, or disruption of critical services. The attack vector is particularly dangerous because it requires minimal privileges to exploit and can be executed remotely without authentication. This makes it an attractive target for automated exploitation tools and represents a significant threat to organizations relying on NIS for network information management.
Security professionals should consider this vulnerability in the context of the CWE-78 weakness category, which specifically addresses "Improper Neutralization of Special Elements used in OS Command Injection Attacks." The flaw aligns with attack patterns documented in the MITRE ATT&CK framework under the T1059 technique for command and scripting interpreter, where adversaries leverage legitimate system tools to execute malicious commands. Organizations should implement immediate mitigations including disabling unnecessary NIS services, restricting network access to NIS servers through firewall rules, and applying patches that properly validate input parameters. Additionally, network segmentation and monitoring should be implemented to detect suspicious NIS traffic patterns and potential exploitation attempts. The vulnerability demonstrates the critical importance of input validation and privilege separation in network services, particularly those handling administrative operations.