CVE-2005-3053 in Linux
Summary
by MITRE
The sys_set_mempolicy function in mempolicy.c in Linux kernel 2.6.x allows local users to cause a denial of service (kernel BUG()) via a negative first argument.
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Analysis
by VulDB Data Team • 06/10/2019
The vulnerability identified as CVE-2005-3053 resides within the Linux kernel's memory policy management subsystem, specifically in the sys_set_mempolicy function located in mempolicy.c. This flaw represents a classic case of input validation failure that can be exploited by local attackers to trigger kernel-level instability. The vulnerability manifests when the function receives a negative value as its first argument, which should theoretically be a valid memory policy identifier or flag. The kernel's insufficient bounds checking and parameter validation mechanisms fail to properly handle this invalid input, leading to unexpected kernel behavior that ultimately results in a kernel BUG() condition.
The technical exploitation of this vulnerability occurs through the manipulation of the memory policy system call interface, where a local user can invoke the sys_set_mempolicy function with a negative integer value as the initial parameter. This parameter typically represents memory policy flags or identifiers that should fall within a defined positive range. When the kernel processes this negative value without proper validation, it fails to account for the invalid input within its internal state management routines. The function's implementation lacks proper error handling for negative inputs, causing the kernel to enter an undefined state where it attempts to process the invalid parameter through its memory management subsystem, ultimately triggering a kernel BUG() macro that terminates the kernel execution.
From an operational perspective, this vulnerability constitutes a significant denial of service risk that can be exploited by any local user with access to the system. The impact extends beyond simple service disruption as the kernel BUG() condition can potentially lead to system crashes, requiring manual rebooting of affected systems. The vulnerability's local nature means that attackers do not require network access or elevated privileges to exploit it, making it particularly dangerous in multi-user environments where privilege escalation might be possible through other means. The root cause of this vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and demonstrates the critical importance of robust parameter validation in kernel space code.
The exploitation of this vulnerability can be analyzed through the ATT&CK framework's privilege escalation and denial of service tactics, as it provides a reliable method for causing system instability that can be leveraged in broader attack chains. Security researchers have noted that such kernel-level flaws often serve as stepping stones for more sophisticated attacks, where the initial denial of service can be used to create conditions favorable for privilege escalation or to mask more complex exploitation attempts. The vulnerability's presence in Linux kernel 2.6.x versions indicates a widespread exposure across numerous systems that were not properly patched, highlighting the importance of maintaining up-to-date kernel security patches.
Mitigation strategies for this vulnerability primarily involve applying the appropriate kernel security patches that were released to address the specific input validation issue in the sys_set_mempolicy function. System administrators should ensure that all affected Linux systems receive the necessary kernel updates that implement proper bounds checking for the memory policy parameters. Additionally, implementing proper system monitoring and intrusion detection mechanisms can help identify potential exploitation attempts through abnormal system behavior or kernel error messages. The vulnerability serves as a reminder of the critical need for rigorous code review processes in kernel development, particularly for functions that handle user-space input and interact with critical system resources. Organizations should also consider implementing kernel hardening measures such as kernel address space layout randomization and other security enhancements that can reduce the impact of similar vulnerabilities in the future.