CVE-2010-4243 in Linux
Summary
by MITRE
fs/exec.c in the Linux kernel before 2.6.37 does not enable the OOM Killer to assess use of stack memory by arrays representing the (1) arguments and (2) environment, which allows local users to cause a denial of service (memory consumption) via a crafted exec system call, aka an "OOM dodging issue," a related issue to CVE-2010-3858.
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Analysis
by VulDB Data Team • 07/01/2024
The vulnerability described in CVE-2010-4243 represents a critical flaw in the Linux kernel's memory management system that specifically affects versions prior to 2.6.37. This issue resides within the fs/exec.c file and fundamentally undermines the operating system's ability to properly account for memory usage during process execution. The flaw creates a scenario where the Out-of-Memory (OOM) killer mechanism fails to accurately assess the total memory consumption of processes, particularly focusing on stack memory allocated for argument and environment arrays. This oversight enables malicious local users to exploit the system by crafting specially designed exec system calls that can consume excessive memory resources without triggering the OOM killer's protective mechanisms.
The technical root cause of this vulnerability stems from the kernel's failure to properly include stack memory usage from argument and environment arrays when calculating memory consumption for OOM decisions. When a process executes a program through the exec system call, the kernel allocates stack space for the argument vector and environment variables, but these allocations are not properly factored into the memory accounting that the OOM killer uses to determine when to terminate processes. This creates a situation where processes can consume large amounts of memory through argument and environment arrays without the system recognizing this as a threat to overall memory availability. The vulnerability operates under CWE-122, which classifies it as an improper restriction of operations within the bounds of a memory buffer, specifically manifesting as a memory consumption issue that bypasses normal resource management controls.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise entire system stability and availability. Local attackers can leverage this flaw to gradually consume system memory resources through multiple crafted exec calls, eventually leading to system instability or complete system crashes. The OOM killer, which serves as a critical safety mechanism to prevent system crashes due to memory exhaustion, becomes ineffective against these specific types of memory consumption attacks. This vulnerability particularly affects systems where memory resources are constrained and where multiple processes might be executing with large argument or environment arrays. The implications are severe because the attack can be executed by any local user with minimal privileges, making it a significant concern for multi-user systems, virtualized environments, and cloud computing platforms where resource isolation is paramount.
Mitigation strategies for CVE-2010-4243 primarily focus on updating to kernel versions 2.6.37 or later where the fix has been implemented. The patch addresses the issue by ensuring that stack memory usage for argument and environment arrays is properly included in the memory accounting calculations that the OOM killer uses to make decisions. System administrators should prioritize kernel updates as a critical security measure, particularly in environments where multiple users have local access or where the system handles sensitive workloads. Additional protective measures include implementing resource limits through systemd or similar process management systems, monitoring memory usage patterns, and configuring appropriate OOM killer settings to provide additional layers of protection. Organizations should also consider implementing process monitoring to detect unusual memory consumption patterns that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1499.001 for network denial of service and T1059.003 for command and scripting interpreter demonstrates its potential for broader attack vectors beyond simple local privilege escalation.