CVE-2011-1495 in Linux
Summary
by MITRE
drivers/scsi/mpt2sas/mpt2sas_ctl.c in the Linux kernel 2.6.38 and earlier does not validate (1) length and (2) offset values before performing memory copy operations, which might allow local users to gain privileges, cause a denial of service (memory corruption), or obtain sensitive information from kernel memory via a crafted ioctl call, related to the _ctl_do_mpt_command and _ctl_diag_read_buffer functions.
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Analysis
by VulDB Data Team • 11/05/2021
The vulnerability identified as CVE-2011-1495 resides within the Linux kernel's SCSI MPT2 SAS driver component, specifically in the mpt2sas_ctl.c file. This flaw represents a classic buffer overflow condition that occurs when the driver fails to properly validate input parameters before executing memory copy operations. The vulnerability affects Linux kernel versions 2.6.38 and earlier, making it a significant concern for systems running these outdated kernel versions. The issue manifests through two primary functions: _ctl_do_mpt_command and _ctl_diag_read_buffer, which handle ioctl commands for managing the MPT2 SAS storage controllers. These functions process user-supplied data without adequate validation of length and offset parameters, creating an exploitable condition that can be leveraged by local attackers.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds writes. The flaw occurs when the driver receives a crafted ioctl command containing malformed length and offset values that exceed the bounds of allocated memory buffers. This improper validation allows attackers to manipulate memory locations beyond the intended buffer boundaries, potentially leading to memory corruption that can be exploited to execute arbitrary code with kernel privileges. The vulnerability's impact extends beyond simple privilege escalation as it can also cause system instability through memory corruption or enable information disclosure attacks that allow adversaries to read sensitive kernel memory contents. The local nature of the attack means that an attacker must already have access to the system, but once inside, they can leverage this flaw to elevate their privileges to root level.
The operational impact of CVE-2011-1495 is substantial for organizations running affected Linux kernel versions, particularly in enterprise environments where SCSI storage systems are prevalent. Systems utilizing MPT2 SAS controllers, which are common in high-performance computing environments, server farms, and data centers, face increased risk of compromise. The vulnerability can be exploited to achieve privilege escalation from a regular user account to root access, providing attackers with complete control over affected systems. Additionally, the memory corruption aspect can lead to system crashes, denial of service conditions, and potential data loss. The attack vector through ioctl calls makes this vulnerability particularly concerning as it can be triggered through legitimate system interfaces, making detection more challenging. Organizations running vulnerable systems may experience service disruptions, unauthorized access to sensitive data, and potential compromise of entire network segments if attackers leverage this vulnerability to establish persistent access.
Mitigation strategies for CVE-2011-1495 focus primarily on kernel version upgrades, as the vulnerability was addressed in subsequent kernel releases. System administrators should immediately upgrade to Linux kernel versions 2.6.39 or later where the vulnerability has been patched. The fix involves implementing proper input validation for length and offset parameters before memory copy operations are performed, ensuring that all user-supplied values fall within acceptable bounds. Organizations should also implement monitoring for suspicious ioctl activity and consider disabling unnecessary SCSI controller interfaces when not actively required. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically T1068, which involves exploiting vulnerabilities to gain elevated privileges. Security teams should conduct comprehensive vulnerability assessments to identify systems running affected kernel versions and prioritize patching efforts. Additionally, implementing kernel module signing and secure boot mechanisms can help prevent exploitation of such vulnerabilities even if patching is delayed. Regular security audits and system hardening practices should include verification of kernel integrity and proper access controls to limit potential attack surfaces for local privilege escalation exploits.