CVE-2005-3108 in Linux
Summary
by MITRE
mm/ioremap.c in Linux 2.6 on 64-bit x86 systems allows local users to cause a denial of service or an information leak via an ioremap on a certain memory map that causes the iounmap to perform a lookup of a page that does not exist.
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Analysis
by VulDB Data Team • 06/10/2019
The vulnerability described in CVE-2005-3108 represents a critical flaw in the Linux kernel's memory management subsystem, specifically within the mm/ioremap.c file that handles memory mapping operations on 64-bit x86 architectures. This issue stems from improper handling of memory mapping operations that can lead to both denial of service conditions and potential information disclosure. The flaw occurs when the ioremap function processes certain memory mappings that subsequently cause the iounmap function to attempt lookups of non-existent pages, creating a scenario where the kernel's memory management logic fails catastrophically.
The technical root cause of this vulnerability lies in the kernel's page table management and memory mapping logic where the iounmap function performs invalid page lookups when dealing with specific memory mapping configurations. This represents a classic case of improper memory management that can be exploited by local users to trigger kernel panics or cause information leaks through memory corruption. The vulnerability specifically affects 64-bit x86 systems running Linux 2.6 kernels, making it particularly concerning for server environments and embedded systems that rely on these architectures. The flaw demonstrates poor error handling in kernel memory management functions and can be categorized under CWE-125: Out-of-bounds Read, as the system attempts to access memory locations that do not exist or are not properly mapped.
From an operational impact perspective, this vulnerability presents significant risks to system availability and data integrity. Local attackers can leverage this flaw to cause system crashes and denial of service conditions that may require system reboot to resolve, potentially disrupting critical services and applications running on affected systems. The information leak aspect of this vulnerability could expose sensitive kernel memory contents to local users, potentially revealing kernel addresses, configuration details, or other confidential information that could aid in more sophisticated attacks. This makes the vulnerability particularly dangerous in multi-tenant environments or systems where local user access cannot be fully trusted.
The mitigation strategies for this vulnerability primarily involve applying the appropriate kernel patches released by the Linux kernel development team, which address the improper page lookup logic in the ioremap and iounmap functions. System administrators should prioritize updating their Linux 2.6 kernel installations to versions containing the fix, as the vulnerability cannot be effectively mitigated through configuration changes alone. Additionally, implementing proper access controls and limiting local user privileges can reduce the attack surface, though this does not eliminate the underlying kernel flaw. Organizations should also consider monitoring for system crashes or unusual memory access patterns that might indicate exploitation attempts, as the vulnerability may be used as a stepping stone for more advanced attacks targeting the kernel itself.
This vulnerability aligns with ATT&CK technique T1068: Exploitation for Privilege Escalation, as local users can leverage memory management flaws to gain elevated privileges or cause system instability. The flaw also relates to T1499.004: Endpoint Denial of Service, as it enables attackers to cause system crashes through memory mapping operations. The vulnerability demonstrates how kernel-level memory management issues can create both availability and confidentiality risks, making it a critical concern for system security. The specific nature of the flaw in the Linux kernel's memory management subsystem highlights the importance of rigorous testing and code review for kernel components that handle memory mapping and page table operations, as these functions are fundamental to system security and stability.