CVE-2011-4330 in Linux
Summary
by MITRE
Stack-based buffer overflow in the hfs_mac2asc function in fs/hfs/trans.c in the Linux kernel 2.6 allows local users to cause a denial of service (crash) and possibly execute arbitrary code via an HFS image with a crafted len field.
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Analysis
by VulDB Data Team • 11/29/2021
The vulnerability identified as CVE-2011-4330 represents a critical stack-based buffer overflow within the Linux kernel version 2.6 operating system. This flaw exists specifically within the hfs_mac2asc function located in the fs/hfs/trans.c file, which is responsible for handling HFS (Hierarchical File System) file operations. The vulnerability arises from insufficient input validation when processing HFS images, particularly when the len field contains maliciously crafted data that exceeds the allocated buffer size on the stack.
The technical implementation of this vulnerability demonstrates a classic stack buffer overflow scenario where the hfs_mac2asc function fails to properly bounds-check the len field parameter before using it to determine buffer allocation or copy operations. When an attacker provides an HFS image containing a crafted len field value, the function attempts to process this data without adequate validation, resulting in memory corruption that can overwrite adjacent stack memory locations. This type of vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack data and potentially control program execution flow.
The operational impact of CVE-2011-4330 extends beyond simple denial of service to potentially enable arbitrary code execution within the kernel context. Local users who can manipulate or mount HFS images on systems running vulnerable kernel versions can leverage this vulnerability to crash the system or execute malicious code with kernel privileges. The attack vector requires local access to the system since mounting HFS images typically requires user-level access, but once exploited, the consequences can be severe as kernel-level code execution provides complete system compromise. This vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and demonstrates how kernel-level vulnerabilities can be exploited to gain elevated privileges.
Systems running Linux kernel versions 2.6.x are particularly vulnerable to this exploit, making it a significant concern for organizations maintaining legacy systems or those that have not properly updated their kernel versions. The vulnerability's exploitation requires minimal privileges and can be triggered through normal file system operations when mounting HFS images. Organizations should prioritize patching their kernel versions to address this vulnerability, as the potential for privilege escalation and system compromise makes it a high-priority security concern. The fix typically involves implementing proper bounds checking within the hfs_mac2asc function to prevent buffer overflows when processing the len field parameter, ensuring that all input values are validated before being used in memory operations.