CVE-2017-17384 in ISPConfig
Summary
by MITRE
ISPConfig 3.x before 3.1.9 allows remote authenticated users to obtain root access by creating a crafted cron job.
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Analysis
by VulDB Data Team • 12/12/2019
The vulnerability identified as CVE-2017-17384 affects ISPConfig 3.x versions prior to 3.1.9 and represents a critical privilege escalation flaw that enables authenticated remote attackers to achieve root access on affected systems. This vulnerability specifically targets the cron job creation functionality within the ISPConfig management interface, exploiting a design flaw that allows malicious users to craft specially constructed cron jobs capable of executing arbitrary commands with elevated privileges. The flaw exists in the way the system handles user input validation and privilege separation during cron job creation processes, creating a pathway for authenticated attackers to bypass normal access controls and escalate their privileges to the root level.
The technical implementation of this vulnerability stems from insufficient input sanitization and inadequate privilege checking mechanisms within the ISPConfig cron job handling code. When authenticated users create cron jobs through the web interface, the system fails to properly validate the cron job parameters and command execution contexts, allowing attackers to inject malicious payloads that can execute with root privileges. This issue falls under CWE-20, which addresses improper input validation, and specifically relates to CWE-78, which deals with OS command injection vulnerabilities. The vulnerability exploits the trust model within the application where legitimate user actions are not sufficiently validated before being executed with system-level privileges, creating a dangerous privilege escalation vector.
The operational impact of CVE-2017-17384 is severe and potentially catastrophic for organizations relying on affected ISPConfig installations. Once an attacker successfully exploits this vulnerability, they gain complete control over the hosting server, including the ability to modify system files, install malware, steal sensitive data, and establish persistent backdoors. The remote nature of the attack means that attackers can exploit this vulnerability from anywhere on the internet without requiring physical access to the system, making it particularly dangerous for web hosting providers and organizations managing multiple client domains. This vulnerability directly maps to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and T1078, which covers 'Valid Accounts' as attackers can leverage legitimate user credentials to escalate their privileges. The attack chain typically involves gaining initial access through legitimate user accounts, creating malicious cron jobs, and then executing commands with root privileges to fully compromise the system.
Organizations affected by this vulnerability should immediately upgrade to ISPConfig version 3.1.9 or later, which includes proper input validation and privilege separation mechanisms to prevent unauthorized privilege escalation. System administrators should also implement additional monitoring and access controls around cron job creation functionality, review existing cron jobs for malicious entries, and conduct thorough security audits of their ISPConfig installations. The mitigation strategy should include network-level restrictions on access to the ISPConfig web interface, implementation of multi-factor authentication, and regular security assessments of the hosting environment to detect potential exploitation attempts. Additionally, organizations should consider implementing intrusion detection systems that can monitor for unusual cron job creation patterns and command execution activities that may indicate exploitation of this vulnerability.