CVE-2021-38994 in AIX
Summary
by MITRE • 02/24/2022
IBM AIX 7.1, 7.2, 7.3, and VIOS 3.1 could allow a non-privileged local user to exploit a vulnerability in the AIX kernel to cause a denial of service. IBM X-Force ID: 213072.
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Analysis
by VulDB Data Team • 02/26/2022
This vulnerability affects IBM AIX operating systems version 7.1, 7.2, 7.3, and VIOS 3.1, representing a significant kernel-level weakness that could be exploited by local users. The flaw manifests as a denial of service condition that can be triggered by non-privileged users, making it particularly concerning for systems where user access controls may not be strictly enforced. The vulnerability resides within the AIX kernel itself, indicating a fundamental issue in the core operating system components that handle system resources and process management. This type of vulnerability falls under the category of kernel-level flaws that can compromise system stability and availability, with potential cascading effects on critical business operations that depend on these systems.
The technical nature of this vulnerability involves a specific kernel mechanism that fails to properly handle certain input conditions or system states, leading to system instability and potential crash scenarios. The exploitation requires local access to the system, meaning that an attacker must already have some level of user access, but does not require elevated privileges. This characteristic places the vulnerability in the CWE-119 category, which deals with memory safety issues and improper handling of system resources. The attack surface is limited to local users but the impact can be severe as it affects the core operating system functionality, potentially rendering the system unusable until manual intervention or system restart occurs.
From an operational standpoint, this vulnerability represents a substantial risk to enterprise environments that rely on AIX systems for critical workloads. The denial of service condition can disrupt business operations and may require immediate system restarts, leading to unplanned downtime and potential data loss. The vulnerability's impact is particularly severe in high-availability environments where system uptime is critical, as it could be exploited to cause service disruption without requiring privileged access. The IBM X-Force ID 213072 indicates that this vulnerability was recognized by IBM's security team and likely has associated threat intelligence and mitigation guidance. Organizations using these AIX versions should be particularly vigilant as the vulnerability affects multiple generations of the operating system, suggesting it may be a persistent issue in the kernel implementation.
Mitigation strategies for this vulnerability should focus on immediate patching and system hardening measures. IBM has released security updates addressing this specific issue, and organizations should prioritize applying these patches to all affected systems. Additionally, implementing proper access controls and monitoring for unusual system behavior can help detect exploitation attempts. The vulnerability's local nature suggests that network-based attacks are not directly possible, but organizations should still monitor for any attempts to escalate privileges through other means. System administrators should consider implementing logging and alerting mechanisms that can detect kernel-level anomalies that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should include verification that systems are not running vulnerable versions of the AIX kernel, particularly in environments where system updates may be delayed or where legacy systems are maintained. The ATT&CK framework would categorize this vulnerability under the T1499 category, which involves disruption of services, and potentially T1068 related to exploit for privilege escalation, though the latter is less applicable given the non-privileged nature of the initial exploitation.