CVE-2005-3359 in Linux
Summary
by MITRE
The atm module in Linux kernel 2.6 before 2.6.14 allows local users to cause a denial of service (panic) via certain socket calls that produce inconsistent reference counts for loadable protocol modules.
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Analysis
by VulDB Data Team • 07/05/2019
The vulnerability described in CVE-2005-3359 represents a critical kernel-level issue affecting the atm module within Linux kernel versions prior to 2.6.14. This flaw resides in the kernel's implementation of Asynchronous Transfer Mode networking support, which is part of the broader network subsystem architecture. The vulnerability manifests when specific socket operations are executed against ATM protocol modules, creating a scenario where reference counting mechanisms become inconsistent. This inconsistency leads to a kernel panic, effectively causing a system crash that results in denial of service for legitimate users and applications relying on the affected system.
The technical root cause of this vulnerability stems from improper reference counting within the kernel's loadable module management system. When certain socket calls are made to the ATM module, the kernel fails to maintain proper accounting of module references, leading to a condition where the module's reference count becomes corrupted. This corruption occurs during the module loading and unloading lifecycle, particularly when modules are being dynamically managed through the kernel's module subsystem. The flaw is classified as a memory management error that can be exploited through local user access, making it particularly dangerous in multi-user environments where privilege escalation might be possible. According to CWE classification, this vulnerability maps to CWE-129, which deals with insufficient bound checking, and CWE-476, which addresses null pointer dereference conditions that can occur due to improper module reference handling.
The operational impact of this vulnerability extends beyond simple system crashes, as it can be leveraged to disrupt critical network services and potentially compromise system availability. Local attackers with minimal privileges can exploit this flaw to trigger kernel panics, effectively rendering the system unusable until manual reboot is performed. This type of denial of service attack can have severe implications in server environments, network infrastructure devices, and any system where continuous availability is critical. The vulnerability is particularly concerning because it affects the core kernel networking subsystem, meaning that successful exploitation can impact all network communications on the affected system. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and denial of service, potentially serving as a stepping stone for more sophisticated attacks.
Mitigation strategies for CVE-2005-3359 primarily focus on immediate kernel updates to versions 2.6.14 and later, where the reference counting issues have been addressed through improved module management routines. System administrators should prioritize patching affected systems, particularly in environments where ATM networking is utilized or where systems might be exposed to untrusted local users. Additional defensive measures include disabling ATM networking support entirely if the functionality is not required, implementing proper access controls to limit local user privileges, and monitoring system logs for signs of kernel panics or unusual network activity. The fix implemented in kernel version 2.6.14 involved correcting the reference counting logic within the module loading subsystem to ensure proper accounting of module references during socket operations. Organizations should also consider implementing network segmentation and access controls to limit potential exploitation vectors while maintaining operational security posture.