CVE-2011-1494 in Linux
Summary
by MITRE
Integer overflow in the _ctl_do_mpt_command function in drivers/scsi/mpt2sas/mpt2sas_ctl.c in the Linux kernel 2.6.38 and earlier might allow local users to gain privileges or cause a denial of service (memory corruption) via an ioctl call specifying a crafted value that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 11/05/2021
The vulnerability described in CVE-2011-1494 represents a critical integer overflow flaw within the Linux kernel's SCSI multipath target driver implementation. This issue resides in the _ctl_do_mpt_command function located in drivers/scsi/mpt2sas/mpt2sas_ctl.c, which is part of the mpt2sas driver responsible for managing SAS (Serial Attached SCSI) storage controllers. The vulnerability affects Linux kernel versions up to and including 2.6.38, making it a significant concern for systems running older kernel versions. The flaw manifests when a local user executes a crafted ioctl call that manipulates a value leading to improper integer arithmetic within the kernel's memory management routines.
The technical exploitation of this vulnerability occurs through a heap-based buffer overflow condition that arises from improper integer overflow handling in the kernel's control interface. When the _ctl_do_mpt_command function processes a malicious ioctl request, it fails to properly validate or constrain integer values that determine buffer allocation sizes. This allows an attacker to specify a crafted value that, when processed through integer arithmetic operations, results in an overflow condition. The overflow subsequently causes the kernel to allocate insufficient memory for buffer operations, leading to memory corruption that can be exploited to execute arbitrary code with kernel privileges. The vulnerability specifically targets the kernel's memory management subsystem where heap allocations are performed based on user-supplied integer values without adequate overflow protection mechanisms.
The operational impact of CVE-2011-1494 extends beyond simple privilege escalation to include potential system instability and complete system compromise. Local attackers who can execute ioctl commands against the affected mpt2sas driver interface can leverage this vulnerability to gain root-level access to the system, effectively bypassing all user-level security controls. Additionally, the memory corruption resulting from the heap overflow can cause system crashes, leading to denial of service conditions that may be exploited by malicious actors to disrupt critical services. The vulnerability is particularly concerning in enterprise environments where storage controllers are frequently managed through kernel interfaces, as it provides a direct path for attackers to escalate privileges within the kernel space. The attack vector requires local access to the system, making it more difficult to exploit remotely but still highly dangerous in environments where local privilege escalation is possible.
Mitigation strategies for CVE-2011-1494 should focus on immediate kernel updates to versions 2.6.39 and later where the integer overflow has been properly addressed through enhanced input validation and proper integer arithmetic handling. System administrators should prioritize patching affected systems and monitor for any signs of exploitation attempts. Additional defensive measures include implementing strict access controls on SCSI controller interfaces, disabling unnecessary kernel modules when possible, and employing kernel hardening techniques such as stack canaries and address space layout randomization. The vulnerability aligns with CWE-190, which describes integer overflow and underflow conditions, and represents a classic example of how improper input validation in kernel space can lead to privilege escalation. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques using kernel exploits and can be categorized under the T1068 technique for exploit for privilege escalation, making it a critical target for security hardening efforts in enterprise environments.