CVE-1999-0785 in INN
Summary
by MITRE
The INN inndstart program allows local users to gain root privileges via the "pathrun" parameter in the inn.conf file.
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Analysis
by VulDB Data Team • 04/19/2026
The vulnerability described in CVE-1999-0785 resides within the INN (InterNetNews) software suite, specifically targeting the inndstart program that manages the news server daemon. This flaw represents a classic privilege escalation vulnerability that allows local attackers to elevate their system privileges from regular user level to root access. The vulnerability is particularly concerning because it operates through a configuration parameter that is typically modified by system administrators, making it a potential vector for persistent attacks that could compromise entire news server infrastructures. The inndstart program serves as the initialization script that reads configuration parameters from the inn.conf file, establishing the foundation for how the news server operates within the system environment.
The technical flaw manifests through the improper handling of the "pathrun" parameter within the inn.conf configuration file. When the inndstart program processes this parameter, it fails to properly validate or sanitize the input provided by local users who have access to modify the configuration file. This inadequate input validation creates a path traversal or command injection scenario where malicious input in the pathrun parameter can be executed with elevated privileges. The vulnerability stems from the program's failure to implement proper access controls or privilege separation mechanisms when processing configuration parameters that could influence system-level operations. According to CWE classification, this vulnerability aligns with CWE-20, which covers Improper Input Validation, and CWE-264, which addresses Permissions, Privileges, and Access Controls, making it a compound weakness that combines multiple security flaws.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally compromises the security model of news server installations that rely on INN software. Local users who can modify the inn.conf file can potentially execute arbitrary commands with root privileges, enabling them to modify system files, install backdoors, or completely compromise the integrity of the news server. This vulnerability particularly affects systems where multiple users have access to modify configuration files or where the inndstart program runs with elevated privileges during initialization. The attack vector is relatively straightforward since it only requires local access to the system and knowledge of the configuration file structure, making it an attractive target for both malicious insiders and external attackers who have gained local footholds. This vulnerability directly corresponds to ATT&CK technique T1068, which covers 'Local Privilege Escalation', and T1548.001, covering 'Abuse Elevation Control Mechanism', as it exploits weak privilege control mechanisms within the system.
Mitigation strategies for this vulnerability require immediate attention to the configuration management practices within INN installations. System administrators should ensure that only authorized personnel have write access to the inn.conf file and that proper file permissions are enforced to prevent unauthorized modifications. The inndstart program should be updated to implement proper input validation and sanitization for all configuration parameters, ensuring that any input is carefully checked against expected formats and values. Additionally, privilege separation mechanisms should be implemented so that the configuration processing occurs with minimal necessary privileges, preventing escalation from occurring during the initialization phase. Organizations should also consider implementing automated monitoring of configuration file changes and establishing proper access control lists to limit who can modify critical system parameters. Regular security audits of configuration files and privilege structures should be conducted to identify and remediate similar vulnerabilities that may exist in other system components. The vulnerability highlights the critical importance of validating all user inputs and implementing least privilege principles in system initialization processes, as these are fundamental security practices that prevent unauthorized privilege escalation scenarios.