CVE-2013-6378 in Linux
Summary
by MITRE
The lbs_debugfs_write function in drivers/net/wireless/libertas/debugfs.c in the Linux kernel through 3.12.1 allows local users to cause a denial of service (OOPS) by leveraging root privileges for a zero-length write operation.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/02/2021
The vulnerability identified as CVE-2013-6378 resides within the Linux kernel's wireless networking subsystem, specifically in the libertas driver implementation. This flaw manifests in the lbs_debugfs_write function located at drivers/net/wireless/libertas/debugfs.c, affecting kernel versions through 3.12.1. The issue represents a classic case of improper input validation where the function fails to adequately handle edge cases during write operations to debug filesystem entries. The vulnerability is particularly concerning because it requires only local user privileges to exploit, making it accessible to any user with access to the system who can leverage root privileges for the specific zero-length write operation.
The technical exploitation of this vulnerability occurs when a malicious user performs a zero-length write operation against the debugfs interface associated with the libertas wireless driver. This particular condition triggers an improper memory access pattern within the lbs_debugfs_write function, causing the kernel to experience an unhandled exception that results in an OOPS condition. The OOPS represents a kernel panic scenario where the operating system encounters an unexpected state and must terminate the offending process while potentially crashing the entire system. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, though in this case the vulnerability manifests as an improper handling of zero-length inputs rather than traditional buffer overflows.
From an operational perspective, this vulnerability creates a significant denial of service risk for systems running affected Linux kernel versions. The ability to cause a kernel OOPS means that legitimate system operations can be interrupted, potentially leading to complete system instability or reboot. The impact extends beyond simple service disruption since kernel-level vulnerabilities can compromise the integrity of the entire system, especially in environments where wireless connectivity is critical. Attackers could exploit this vulnerability to repeatedly cause system crashes, effectively rendering the device unusable for its intended wireless networking purposes. This type of vulnerability is particularly dangerous in embedded systems or network infrastructure devices where continuous operation is essential.
The attack vector for CVE-2013-6378 requires local access and the ability to perform write operations against the debugfs filesystem, making it accessible to any user with sufficient privileges. While the vulnerability itself is limited to causing denial of service rather than arbitrary code execution, the potential for system instability makes it a serious concern for system administrators. The exploitation process is straightforward, requiring only a zero-length write operation to trigger the problematic code path. This vulnerability is categorized under the ATT&CK framework as a privilege escalation technique, specifically targeting kernel-level security controls through improper input validation. Organizations should prioritize patching affected systems, as the fix typically involves adding proper bounds checking to handle zero-length write operations in the debugfs interface. System administrators should also consider implementing monitoring for unusual debugfs write operations and ensure that debug filesystem interfaces are properly restricted in production environments to minimize exposure.