CVE-2004-0178 in Linux
Summary
by MITRE
The OSS code for the Sound Blaster (sb16) driver in Linux 2.4.x before 2.4.26, when operating in 16 bit mode, does not properly handle certain sample sizes, which allows local users to cause a denial of service (crash) via a sample with an odd number of bytes.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/04/2019
The vulnerability described in CVE-2004-0178 affects the Open Sound System implementation within the Linux kernel version 2.4.x series, specifically impacting the Sound Blaster sb16 audio driver. This issue resides in the kernel's audio subsystem where the OSS code fails to properly validate sample data when operating in 16 bit mode. The flaw manifests when the system processes audio samples that contain an odd number of bytes, creating a condition that can be exploited to trigger system instability.
The technical root cause of this vulnerability stems from inadequate boundary checking within the audio driver's sample processing routines. When the sb16 driver operates in 16 bit mode, it expects audio samples to be properly aligned and sized according to specific byte boundaries. However, the driver code does not correctly handle cases where sample data contains an odd number of bytes, leading to memory access violations or buffer overflows during audio processing. This particular weakness aligns with CWE-129, which addresses improper validation of input boundaries, and represents a classic example of insufficient input sanitization in kernel-level code.
The operational impact of this vulnerability is significant for systems running affected Linux kernel versions, as local users can exploit this weakness to cause system crashes or denial of service conditions. The attack requires only local access to the system, making it particularly dangerous in multi-user environments where privilege escalation is not necessary. When an audio application submits a sample with an odd byte count, the kernel's audio subsystem crashes, potentially bringing the entire audio functionality to a halt and affecting system stability. This vulnerability specifically maps to attack techniques described in the MITRE ATT&CK framework under the T1499 category for network denial of service, though it operates at the kernel level rather than network infrastructure.
Mitigation strategies for this vulnerability involve upgrading to Linux kernel version 2.4.26 or later, which contains the necessary patches to properly handle odd byte sample sizes in the OSS sound driver. System administrators should also implement proper access controls to limit local user privileges and monitor audio application behavior for anomalous sample processing patterns. Additionally, organizations should maintain current kernel security patches and consider implementing kernel hardening measures such as stack canaries and address space layout randomization to reduce the overall attack surface. The fix implemented in kernel 2.4.26 demonstrates proper input validation techniques that ensure audio sample data is correctly aligned regardless of byte count, thereby preventing the memory access violations that previously led to system crashes.