CVE-2010-4072 in Linux
Summary
by MITRE
The copy_shmid_to_user function in ipc/shm.c in the Linux kernel before 2.6.37-rc1 does not initialize a certain structure, which allows local users to obtain potentially sensitive information from kernel stack memory via vectors related to the shmctl system call and the "old shm interface."
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/05/2021
The vulnerability identified as CVE-2010-4072 represents a classic information disclosure flaw within the Linux kernel's shared memory implementation. This issue resides in the copy_shmid_to_user function located in ipc/shm.c, where a critical oversight occurs during the handling of shared memory segments. The vulnerability affects Linux kernel versions prior to 2.6.37-rc1 and stems from the improper initialization of a structure during the processing of shmctl system calls that utilize the legacy shared memory interface. The flaw manifests when local users exploit the interaction between the shmctl system call and the old shared memory interface to potentially access sensitive data residing in kernel stack memory.
The technical mechanism behind this vulnerability aligns with CWE-1286, which addresses improper initialization of structures in kernel space. When the copy_shmid_to_user function processes shared memory control operations, it fails to properly initialize certain fields within the structure before returning data to user space. This incomplete initialization leaves residual data from previous kernel operations present in memory locations that are subsequently exposed to user-level processes. The old shm interface specifically refers to the legacy shared memory system calls that were maintained for backward compatibility, making this vulnerability particularly concerning as it affects older kernel versions that many systems still utilize.
From an operational perspective, this vulnerability enables local attackers to extract potentially sensitive information from kernel stack memory, which could include cryptographic keys, passwords, or other confidential data that was previously stored in the kernel's memory space. The impact extends beyond simple information disclosure as the leaked data could potentially be leveraged in conjunction with other vulnerabilities to escalate privileges or conduct more sophisticated attacks. Attackers can exploit this through the shmctl system call with specific command parameters that trigger the vulnerable code path, making it a relatively straightforward local privilege escalation vector.
The vulnerability demonstrates characteristics consistent with ATT&CK technique T1003.001, which involves OS credential dumping through kernel memory access. This flaw represents a significant security concern for systems running affected kernel versions, particularly in environments where local user access is not strictly controlled. The remediation approach requires updating to kernel versions 2.6.37-rc1 or later, where the structure initialization issue has been addressed. Organizations should prioritize patching systems running affected kernel versions, as the vulnerability does not require special privileges beyond local user access and can be exploited by any local user with knowledge of the specific system call interface. Additionally, system administrators should consider implementing monitoring for unusual shmctl system call patterns and conduct regular security assessments to identify potentially vulnerable systems that may have been overlooked during standard patch management processes.