CVE-2000-0177 in DNSTools
Summary
by MITRE
DNSTools CGI applications allow remote attackers to execute arbitrary commands via shell metacharacters.
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Analysis
by VulDB Data Team • 08/02/2024
The vulnerability described in CVE-2000-0177 represents a critical command injection flaw within DNSTools CGI applications that enables remote attackers to execute arbitrary commands on affected systems. This vulnerability stems from insufficient input validation and improper sanitization of user-supplied data within the CGI scripts that handle DNS-related operations. The flaw allows malicious actors to inject shell metacharacters into input fields, which are then processed by the system without adequate filtering or escaping mechanisms. The affected DNSTools applications likely process user input through shell commands to perform DNS lookups, zone transfers, or other network operations, creating an avenue for attackers to escalate privileges and gain unauthorized access to underlying system resources.
This vulnerability directly maps to CWE-77 which defines improper neutralization of special elements used in a command shell, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter. The technical implementation involves the CGI application's failure to properly escape or validate input parameters that are subsequently passed to shell execution functions. When users provide input containing metacharacters such as semicolons, ampersands, or backticks, these characters are interpreted by the shell as command delimiters or operators rather than literal input, allowing attackers to chain commands and execute arbitrary code with the privileges of the web server process. The impact extends beyond simple command execution to potential system compromise, data exfiltration, and lateral movement within network environments.
The operational impact of CVE-2000-0177 is severe and multifaceted, potentially allowing attackers to gain full control over affected systems. An attacker could leverage this vulnerability to install backdoors, modify DNS records to redirect traffic, access sensitive configuration files, or use the compromised system as a pivot point for attacking other network resources. The vulnerability affects systems where DNSTools CGI applications are deployed, particularly those running on Unix-like operating systems where shell command execution is common. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access or prior authentication, making it particularly dangerous for publicly accessible web applications. Organizations using these applications face significant risk of data breaches, service disruption, and potential regulatory compliance violations.
Mitigation strategies for CVE-2000-0177 should focus on implementing robust input validation and sanitization practices to prevent command injection attacks. System administrators should immediately apply vendor patches or updates to address the vulnerability, while also implementing proper input filtering mechanisms that escape or sanitize all user-supplied data before processing. The recommended approach includes using parameterized interfaces instead of shell command construction, implementing proper access controls to limit CGI script permissions, and employing web application firewalls to detect and block suspicious input patterns. Additionally, organizations should consider implementing network segmentation to limit the impact of potential compromise, regularly monitoring system logs for signs of exploitation attempts, and conducting security assessments to identify similar vulnerabilities in other applications. The remediation process should also include disabling unnecessary CGI functionality and ensuring that web server processes run with minimal required privileges to limit potential damage from successful exploitation attempts.