CVE-2000-0274 in Linux Trustees
Summary
by MITRE
The Linux trustees kernel patch allows attackers to cause a denial of service by accessing a file or directory with a long name.
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Analysis
by VulDB Data Team • 11/17/2024
The vulnerability identified as CVE-2000-0274 resides within the Linux kernel's trustees patch implementation, which introduces a critical flaw in file system handling mechanisms. This vulnerability specifically affects systems implementing the trustees security model that extends traditional unix permissions with additional access controls. The flaw manifests when the kernel processes file or directory names exceeding certain length thresholds, creating a condition where legitimate system operations can be disrupted through carefully crafted file naming sequences.
The technical implementation of this vulnerability stems from insufficient input validation within the kernel's file name processing routines. When a file or directory is accessed with an excessively long name, the trustees patch fails to properly handle the boundary conditions, leading to memory corruption or stack overflow conditions that ultimately result in system instability. The vulnerability operates at the kernel level where buffer management and string processing functions do not adequately enforce maximum name length constraints, creating a scenario where malicious users can exploit this weakness through crafted file operations.
This vulnerability presents significant operational impact across various Linux distributions that implement the trustees security model, particularly affecting systems where security through extended access controls is paramount. The denial of service condition can render entire file systems inaccessible or cause complete system crashes, impacting availability of critical services and data access. Organizations relying on trustees-based security models for enhanced access control mechanisms face potential operational disruptions that could affect business continuity and system reliability.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and demonstrates characteristics consistent with improper input validation patterns. From an attack perspective, this flaw maps to ATT&CK technique T1499.004, which involves network denial of service attacks through resource exhaustion or system instability. The exploitation requires minimal privileges and can be executed through standard file system operations, making it particularly dangerous as it can be leveraged by both malicious insiders and external attackers to disrupt system availability.
Mitigation strategies should focus on implementing kernel updates that address the buffer handling issues within the trustees patch implementation. System administrators should prioritize applying security patches from their respective Linux distributions that contain fixes for this specific buffer overflow condition. Additionally, implementing proper input validation at the application level and monitoring file system operations for unusually long names can provide additional defense in depth. Organizations should also consider temporarily disabling trustees functionality until proper patches are deployed, though this approach may compromise the intended security benefits of the model.