CVE-2011-1017 in Linux
Summary
by MITRE
Heap-based buffer overflow in the ldm_frag_add function in fs/partitions/ldm.c in the Linux kernel 2.6.37.2 and earlier might allow local users to gain privileges or obtain sensitive information via a crafted LDM partition table.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/28/2024
The vulnerability identified as CVE-2011-1017 represents a critical heap-based buffer overflow in the Linux kernel's Logical Disk Manager implementation. This flaw exists within the ldm_frag_add function located in fs/partitions/ldm.c, affecting kernel versions up to and including 2.6.37.2. The vulnerability arises from insufficient input validation when processing LDM partition tables, creating a condition where maliciously crafted partition data can trigger memory corruption. The issue falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions, though this instance manifests in heap memory due to the dynamic allocation patterns involved in partition table processing. The vulnerability's classification aligns with ATT&CK technique T1068, which covers exploit for privilege escalation through local vulnerabilities.
The technical implementation of this vulnerability exploits the manner in which the Linux kernel handles Logical Disk Manager partition tables during device initialization and partition discovery processes. When a system encounters a partition table formatted according to the LDM specification, the ldm_frag_add function processes fragment information within the partition structure. The flaw occurs because the function fails to properly validate the size of incoming fragment data before copying it into allocated heap memory buffers. This insufficient boundary checking allows an attacker to overflow the allocated buffer space, potentially overwriting adjacent memory regions including function pointers, return addresses, or sensitive kernel data structures. The heap-based nature of the overflow means that the memory corruption occurs in dynamically allocated regions rather than fixed stack locations, making exploitation more complex but still viable for privilege escalation attacks.
The operational impact of CVE-2011-1017 extends beyond simple privilege escalation to encompass potential information disclosure and system stability compromise. Local attackers with access to create or modify LDM partition tables can leverage this vulnerability to execute arbitrary code with kernel-level privileges, effectively bypassing all user-mode security controls. The attack vector requires local system access and the ability to manipulate partition table data, which can be achieved through various means including physical access, malicious storage device insertion, or exploitation of other vulnerabilities that allow partition table modification. The vulnerability's presence in the core partition handling code means that any system utilizing LDM partition tables during boot or partition scanning processes becomes susceptible to exploitation. Additionally, the information disclosure aspect of this vulnerability could expose kernel memory contents, potentially revealing sensitive data structures, cryptographic keys, or other confidential information that might aid in further exploitation attempts.
Mitigation strategies for CVE-2011-1017 require immediate kernel version updates to patched releases where the buffer overflow has been corrected through proper input validation and memory boundary checks. System administrators should prioritize updating to kernel versions 2.6.38 or later, where the vulnerability has been addressed through enhanced validation of LDM partition table data. The fix implemented in the patched versions involves adding comprehensive size validation checks before buffer copying operations, ensuring that fragment data lengths do not exceed allocated buffer capacities. Organizations should also implement monitoring for suspicious partition table modifications and consider disabling LDM partition table support entirely if the functionality is not required. Additional defensive measures include enabling kernel address space layout randomization and other exploit mitigation techniques, though these provide only partial protection against this specific vulnerability. The remediation process should also include comprehensive system auditing to identify any systems running vulnerable kernel versions and thorough testing of updated kernels to ensure continued system stability and functionality.