CVE-2011-1577 in Linux
Summary
by MITRE
Heap-based buffer overflow in the is_gpt_valid function in fs/partitions/efi.c in the Linux kernel 2.6.38 and earlier allows physically proximate attackers to cause a denial of service (OOPS) or possibly have unspecified other impact via a crafted size of the EFI GUID partition-table header on removable media.
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Analysis
by VulDB Data Team • 11/05/2021
The vulnerability identified as CVE-2011-1577 represents a critical heap-based buffer overflow within the Linux kernel's handling of EFI GUID Partition Table (GPT) structures. This flaw exists in the is_gpt_valid function located in fs/partitions/efi.c of kernel versions 2.6.38 and earlier, specifically affecting systems that process removable media containing crafted GPT headers. The vulnerability is classified as a heap overflow under CWE-121, which directly relates to memory allocation and deallocation issues where data is written beyond the boundaries of allocated heap memory regions.
The technical exploitation of this vulnerability occurs when the Linux kernel encounters a malformed EFI GUID Partition Table header on removable storage devices. The is_gpt_valid function fails to properly validate the size parameter of the GPT header structure before processing it, allowing attackers who are physically proximate to the target system to craft malicious partition table data. When the kernel attempts to parse this malformed header, it writes data beyond the allocated buffer boundaries in the heap memory, resulting in memory corruption that can trigger a kernel oops condition or potentially lead to more severe consequences including arbitrary code execution.
The operational impact of CVE-2011-1577 extends beyond simple denial of service scenarios, as the vulnerability can be leveraged by attackers with physical access to cause system instability or potentially achieve privilege escalation. The proximity requirement limits the attack surface but does not eliminate the threat, particularly in environments where removable media is frequently handled or in scenarios where an attacker can influence the insertion of malicious storage devices. This vulnerability directly maps to ATT&CK technique T1059.007 for kernel-mode rootkits and T1021.002 for remote services, as it affects the kernel's ability to properly validate and process external data inputs.
Mitigation strategies for this vulnerability require immediate kernel updates to versions 2.6.39 or later where the buffer overflow has been addressed through proper input validation and bounds checking. System administrators should implement strict media handling policies that prevent unauthorized removable media insertion and employ automated scanning solutions to detect and quarantine suspicious storage devices. The fix implemented in the patched kernel versions includes enhanced validation of the GPT header size parameter before memory allocation and proper bounds checking during header processing. Additionally, organizations should consider implementing kernel module signing and trusted boot processes to prevent exploitation through malicious kernel modifications, while also monitoring for unusual kernel oops events that may indicate attempted exploitation of this vulnerability.