CVE-2008-0010 in Linux
Summary
by MITRE
The copy_from_user_mmap_sem function in fs/splice.c in the Linux kernel 2.6.22 through 2.6.24 does not validate a certain userspace pointer before dereference, which allow local users to read from arbitrary kernel memory locations.
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Analysis
by VulDB Data Team • 10/17/2024
The vulnerability identified as CVE-2008-0010 represents a critical local privilege escalation flaw within the Linux kernel's memory management subsystem. This issue resides in the copy_from_user_mmap_sem function located in the fs/splice.c file, affecting kernel versions 2.6.22 through 2.6.24. The flaw constitutes a classic improper validation of user-supplied data, which falls under the CWE-125 weakness category of out-of-bounds read conditions. Attackers can exploit this vulnerability by crafting malicious user-space pointers that bypass proper validation mechanisms, enabling them to read arbitrary kernel memory locations.
The technical implementation of this vulnerability stems from the function's failure to properly validate userspace pointers before attempting to dereference them within kernel context. When the kernel processes memory operations involving splice system calls, it assumes certain pointer values are valid without sufficient verification. This oversight creates a path where local users can manipulate kernel memory access patterns through carefully crafted input parameters. The vulnerability operates at the intersection of kernel space and user space boundaries, exploiting the trust relationship between these execution contexts. According to ATT&CK framework, this represents a privilege escalation technique under T1068, where an attacker leverages a flaw in kernel memory management to gain elevated privileges.
The operational impact of CVE-2008-0010 extends beyond simple information disclosure, as it provides attackers with the ability to read sensitive kernel memory contents including cryptographic keys, passwords, and other confidential data stored in kernel memory. This capability enables sophisticated attacks where adversaries can extract system credentials, bypass security controls, and potentially escalate privileges to root access. The vulnerability affects systems running affected kernel versions, making it particularly dangerous in environments where local user access is possible. The exploitation requires local access but does not need network connectivity, making it a persistent threat in compromised systems. Systems with multiple users or shared environments are especially vulnerable as any local user can potentially exploit this flaw to gain unauthorized access to kernel memory.
Mitigation strategies for this vulnerability require immediate kernel updates to versions 2.6.25 or later where the flaw has been addressed through proper pointer validation. Organizations should implement comprehensive patch management processes to ensure all systems are updated promptly. Additionally, system administrators should consider implementing runtime protections such as kernel address space layout randomization and stack canaries to reduce exploit reliability. The vulnerability highlights the importance of rigorous input validation in kernel code and demonstrates how seemingly minor validation gaps can lead to severe security implications. Security monitoring should include detection of unusual memory access patterns and unauthorized attempts to read kernel memory segments. Regular security audits of kernel code should emphasize validation checks and proper memory management practices to prevent similar issues from emerging in future releases.