CVE-2005-1368 in Linux
Summary
by MITRE
The key_user_lookup function in security/keys/key.c in Linux kernel 2.6.10 to 2.6.11.8 may allow attackers to cause a denial of service (oops) via SMP.
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Analysis
by VulDB Data Team • 06/02/2019
The vulnerability described in CVE-2005-1368 represents a critical flaw in the Linux kernel's key management subsystem that specifically affects versions 2.6.10 through 2.6.11.8. This issue resides within the key_user_lookup function located in the security/keys/key.c file, which is responsible for managing user keyring lookups and authentication processes. The vulnerability manifests as a kernel oops condition that occurs under specific multi-processor system configurations, making it particularly dangerous in environments utilizing symmetric multiprocessing architectures. The flaw demonstrates a classic race condition or improper synchronization issue that can lead to system instability and complete service disruption.
The technical implementation of this vulnerability stems from inadequate synchronization mechanisms within the kernel's key management code when handling concurrent access requests across multiple processors. When multiple processors attempt to access or modify key user data structures simultaneously, the key_user_lookup function fails to properly coordinate these operations, resulting in memory corruption and subsequent kernel panic conditions. This type of vulnerability falls under the CWE-362 category of "Concurrent Execution using Shared Resource with Improper Synchronization" and aligns with ATT&CK technique T1499.004 for network denial of service. The flaw specifically exploits the kernel's inability to maintain data consistency when multiple threads or processors attempt to access the same key_user structure concurrently, leading to unpredictable behavior and system crashes.
The operational impact of this vulnerability extends beyond simple system instability, as it can be leveraged by malicious actors to perform denial of service attacks against Linux systems running affected kernel versions. An attacker capable of executing code on a target system or simply initiating the appropriate sequence of operations can trigger the vulnerability on SMP systems, causing the kernel to generate an oops message and potentially leading to complete system reboot or hang. This makes the vulnerability particularly dangerous in server environments where uptime and availability are critical, as it can be exploited to disrupt services without requiring elevated privileges or complex attack vectors. The vulnerability affects all systems utilizing the affected kernel versions and multi-processor configurations, making it a widespread concern across enterprise and cloud deployments.
Mitigation strategies for CVE-2005-1368 primarily involve immediate kernel version updates to patched releases that address the synchronization issues within the key_user_lookup function. System administrators should prioritize upgrading to kernel versions 2.6.11.9 or later, where the race condition has been resolved through proper mutex locking and synchronization mechanisms. Additionally, organizations can implement temporary workarounds such as disabling keyring functionality or limiting concurrent access to key management operations, though these approaches may impact system functionality and usability. The fix implemented in patched versions typically involves adding appropriate locking primitives to ensure that only one processor can access the key_user structure at any given time, preventing the memory corruption that leads to kernel oops conditions. Security monitoring should also include detection of kernel oops messages and system instability patterns that may indicate exploitation attempts, as these vulnerabilities often leave traces in system logs and kernel message buffers.