CVE-2024-53150 Overview
CVE-2024-53150 is an out-of-bounds read vulnerability in the Linux kernel's ALSA (Advanced Linux Sound Architecture) USB-audio driver. The vulnerability exists in the code responsible for traversing clock descriptors during USB audio device initialization. When a malicious or malformed USB audio device provides descriptors with shorter-than-expected bLength fields, the driver fails to validate these lengths before accessing descriptor data, resulting in out-of-bounds memory reads.
This vulnerability is particularly concerning because it affects a core kernel subsystem and can be triggered through physical access to a system via a malicious USB device, or potentially through virtualized USB passthrough scenarios.
Critical Impact
This vulnerability has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating active exploitation in the wild. Successful exploitation can lead to disclosure of sensitive kernel memory contents and potential system crashes, affecting both confidentiality and availability.
Affected Products
- Linux Kernel (multiple versions)
- Debian Linux 11.0
Discovery Timeline
- December 24, 2024 - CVE-2024-53150 published to NVD
- November 4, 2025 - Last updated in NVD database
Technical Details for CVE-2024-53150
Vulnerability Analysis
The vulnerability resides in the USB-audio driver's clock descriptor traversal functions within the ALSA subsystem. When processing USB Audio Class 2 (UAC2) and USB Audio Class 3 (UAC3) devices, the kernel must parse various clock descriptors including clock sources, clock selectors, and clock multipliers.
The core issue is that the driver code iterates through descriptor chains without validating that each descriptor's bLength field is sufficiently large to contain the expected data structure. USB descriptors include a bLength field that indicates the total size of the descriptor in bytes. A malformed device can provide a bLength value smaller than the actual structure size the kernel expects to read.
When the kernel accesses fields beyond the actual descriptor boundary, it reads from adjacent memory locations that may contain sensitive kernel data or unmapped memory regions. For clock selector descriptors specifically, the issue is compounded because these structures contain variable-length arrays (bNrInPins elements) plus additional trailing fields, requiring more complex bounds checking.
Root Cause
The root cause is insufficient input validation in the USB-audio descriptor parsing code. The validator functions responsible for traversing clock descriptors do not verify that the bLength field of each descriptor is at least as large as the minimum structure size before accessing structure members.
For clock source and clock multiplier descriptors, the code should verify bLength >= sizeof(descriptor_type). For clock selector descriptors in UAC2 and UAC3, additional validation must account for the variable-length bCSourceID array (with bNrInPins elements) and the two trailing fields (bmControls and iClockSelector).
Attack Vector
The vulnerability requires local access to connect a malicious USB audio device, or can potentially be exploited through virtualized USB passthrough in cloud or containerized environments. An attacker would craft a USB device that presents itself as a USB Audio Class 2 or 3 compliant device but provides malformed clock descriptors with truncated bLength values.
When the victim system enumerates the device, the kernel's USB-audio driver processes the malformed descriptors, triggering out-of-bounds reads. This can be weaponized to leak kernel memory contents (potentially including cryptographic keys, credentials, or ASLR information) or cause a denial of service through kernel panic.
Detection Methods for CVE-2024-53150
Indicators of Compromise
- Unexpected kernel crashes or panics related to the snd-usb-audio module
- Unusual USB device connection events in system logs, particularly for audio class devices with malformed descriptors
- Kernel log messages indicating ALSA subsystem errors during USB audio device enumeration
- Memory corruption symptoms or unexplained system instability following USB device connections
Detection Strategies
- Monitor dmesg and kernel logs for errors originating from the snd-usb-audio driver module
- Implement USB device whitelisting to prevent unauthorized USB audio devices from being enumerated
- Use SentinelOne's kernel-level monitoring to detect anomalous memory access patterns associated with USB driver operations
- Deploy kernel audit rules to track USB device attachment events: auditctl -w /sys/bus/usb/devices -p rwxa -k usb_audit
Monitoring Recommendations
- Enable comprehensive logging for USB subsystem events via usbmon or similar kernel tracing facilities
- Monitor for signs of kernel memory disclosure or attempted information exfiltration following USB device connections
- Implement behavioral detection for unusual patterns of USB device enumeration, particularly devices that trigger driver errors
- Review system logs regularly for patterns indicating exploit attempts against kernel USB drivers
How to Mitigate CVE-2024-53150
Immediate Actions Required
- Apply kernel patches immediately, as this vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog
- Restrict physical access to systems and disable unused USB ports where possible
- Consider blacklisting the snd-usb-audio module on systems that do not require USB audio functionality
- For Debian systems, apply the security updates referenced in the Debian LTS announcements
Patch Information
The Linux kernel maintainers have released patches that add sanity checks to the validator functions for clock descriptor traversal. The fix ensures that when the descriptor bLength is shorter than expected, the descriptor is skipped in the traversal loop.
Patches are available through the following kernel.org commits:
- Commit 096bb5b43edf
- Commit 45a92cbc88e4
- Commit 74cb86e1006c
- Commit a3dd4d63eeb4
- Commit a632bdcb359f
- Commit ab011f7439d9
- Commit da13ade87a12
- Commit ea0fa76f61cf
Debian users should refer to the Debian LTS Security Announcements for distribution-specific updates.
Workarounds
- Blacklist the snd-usb-audio kernel module on systems where USB audio is not required using modprobe.blacklist=snd-usb-audio
- Implement USB device authorization policies to prevent automatic enumeration of unknown USB devices
- Use USBGuard or similar tools to create whitelists of trusted USB devices
- Physically disable or block USB ports on sensitive systems
# Blacklist the vulnerable USB-audio module
echo "blacklist snd-usb-audio" | sudo tee /etc/modprobe.d/disable-usb-audio.conf
# Prevent module from loading immediately
sudo modprobe -r snd-usb-audio
# Disable USB device auto-authorization (requires reboot or USB subsystem reload)
echo 0 | sudo tee /sys/bus/usb/devices/usb*/authorized_default
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
