CVE-2009-0784 in SystemTap
Summary
by MITRE
Race condition in the SystemTap stap tool 0.0.20080705 and 0.0.20090314 allows local users in the stapusr group to insert arbitrary SystemTap kernel modules and gain privileges via unknown vectors.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/27/2025
The vulnerability identified as CVE-2009-0784 represents a critical race condition flaw within the SystemTap stap tool version 0.0.20080705 and 0.0.20090314 which fundamentally compromises system security through improper privilege management. This issue specifically affects systems where users belong to the stapusr group, creating an exploitable pathway for local privilege escalation. The race condition manifests during the execution of SystemTap kernel modules, where insufficient synchronization mechanisms allow malicious users to manipulate the system state between critical operations. Such vulnerabilities fall under the CWE-362 category of Race Conditions, which represents one of the most dangerous classes of software defects due to their inherent timing-dependent nature that makes them particularly challenging to detect and prevent.
The technical exploitation of this vulnerability occurs through the manipulation of kernel module insertion processes within the SystemTap framework, where attackers can leverage the race condition to inject arbitrary kernel modules with elevated privileges. This occurs because the stap tool does not properly validate or synchronize access to kernel module loading mechanisms during the compilation and execution phases of SystemTap scripts. The flaw enables local users who are members of the stapusr group to bypass normal security controls and execute malicious kernel code that can escalate privileges to root level access. This represents a severe operational impact as it transforms a local user account into a system administrator level privilege, potentially allowing attackers to establish persistent access, modify system files, or exfiltrate sensitive data.
The operational implications of this vulnerability extend beyond simple privilege escalation, as it fundamentally undermines the security model of systems utilizing SystemTap for performance monitoring and debugging. Attackers can exploit this condition to create backdoors, disable security mechanisms, or perform other malicious activities that would normally require administrative privileges. The vulnerability is particularly concerning in environments where SystemTap is deployed with elevated privileges or where users in the stapusr group have access to systems that are not properly segmented. From an attack perspective, this vulnerability aligns with ATT&CK technique T1068 which focuses on exploiting local privilege escalation opportunities, and T1543 which covers privilege escalation through kernel modules.
Mitigation strategies for CVE-2009-0784 require immediate patching of affected SystemTap versions, as the vulnerability cannot be effectively addressed through configuration changes alone due to its fundamental design flaw in the race condition handling. Organizations should implement strict access controls to prevent unauthorized users from joining the stapusr group, while also monitoring for suspicious SystemTap module loading activities. The recommended approach includes upgrading to patched versions of SystemTap, removing unnecessary membership in the stapusr group, and implementing monitoring solutions that can detect unauthorized kernel module insertion attempts. Additionally, system administrators should consider disabling SystemTap functionality when not actively required, as this reduces the attack surface and eliminates the potential for exploitation. The vulnerability demonstrates the critical importance of proper synchronization mechanisms in security-sensitive code, particularly when dealing with kernel-level operations that can directly impact system integrity and privilege boundaries.