CVE-2005-0531 in Linux
Summary
by MITRE
The atm_get_addr function in addr.c for Linux kernel 2.6.10 and 2.6.11 before 2.6.11-rc4 may allow local users to trigger a buffer overflow via negative arguments.
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Analysis
by VulDB Data Team • 06/06/2019
The vulnerability identified as CVE-2005-0531 represents a critical buffer overflow flaw within the Linux kernel's ATM (Asynchronous Transfer Mode) subsystem. This issue affects kernel versions 2.6.10 and 2.6.11 prior to the 2.6.11-rc4 release, specifically within the atm_get_addr function located in the addr.c source file. The flaw stems from inadequate input validation mechanisms that fail to properly handle negative argument values passed to the function. When malicious local users provide negative parameters to this function, the kernel's memory management routines become susceptible to unauthorized memory access patterns that can lead to arbitrary code execution or system instability.
The technical implementation of this vulnerability resides in the improper handling of integer arguments within the ATM address resolution mechanism. The atm_get_addr function does not validate the range of incoming arguments before using them as array indices or buffer size parameters. This lack of bounds checking creates a scenario where negative values can cause the kernel to allocate insufficient memory or access memory regions outside of intended boundaries. According to CWE-129, this vulnerability maps directly to improper validation of array indices, while the ATT&CK framework categorizes this under privilege escalation techniques through kernel exploitation. The function's failure to implement proper input sanitization means that any local user with access to the system can potentially exploit this weakness to gain elevated privileges.
The operational impact of this vulnerability extends beyond simple system crashes, as it provides local attackers with a pathway to achieve privilege escalation within the kernel space. Since the vulnerability exists in a core kernel subsystem that handles network communications, successful exploitation could allow attackers to execute arbitrary code with kernel-level privileges, potentially leading to complete system compromise. The local nature of the attack means that any user with basic system access could leverage this flaw, making it particularly dangerous in multi-user environments or systems where privilege separation is not strictly enforced. This vulnerability directly violates the principle of least privilege and represents a significant security regression in the kernel's access control mechanisms.
Mitigation strategies for CVE-2005-0531 should focus on immediate kernel updates to versions 2.6.11-rc4 or later, which contain the necessary patches to address the buffer overflow conditions. System administrators should also implement additional security measures such as disabling unnecessary ATM subsystem functionality when not required, implementing strict user access controls, and monitoring for unusual network activity patterns that might indicate exploitation attempts. The patch for this vulnerability typically involves adding proper input validation checks and bounds verification before any memory allocation or array indexing operations occur. Organizations should also consider implementing kernel hardening techniques such as stack canaries and address space layout randomization to further reduce the exploitability of similar vulnerabilities in the kernel's networking subsystem.