CVE-2025-55095
MediumCVSS 4.2Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
The _ux_host_class_storage_media_mount() function mounts partitions on a USB mass storage device and, upon encountering an extended partition entry, recursively calls itself to mount the next logical partition. There is no limit on recursion depth or tracking of visited sectors, so a malicious or malformed disk image can include cyclic or excessively deep chains of extended partitions, causing stack overflow.
Risk Assessment
Connecting a malicious or malformed USB drive can cause stack overflow and system crash (denial of service). Depending on context, this may lead to device instability or service interruption.
Recommendation
Update the USB stack (USBX) to a version that limits recursion and tracks visited sectors. Avoid connecting unknown USB media to sensitive devices.
Other vulnerabilities in USBX
See all- CVE-2026-96402Medium
A malicious USB MTP/PTP device can cause the USBX host to read past a heap buffer during ordinary object enumeration, leaking adjacent heap contents to the application or faulting on an unmapped page.
- CVE-2026-96582Medium
The USBX host stack has a vulnerability where HID report descriptor parsing checks item size only after advancing past the header and parsing the payload, and does not compare declared sizes against actual received bytes. A HID peripheral returning a short report descriptor causes a heap out-of-bounds read during ordinary enumeration.
- CVE-2026-96406Medium
The USBX host stack has a vulnerability in the VideoStreaming interface where the wTotalLength field is used as a budget for walking descriptors without validating against the actual received configuration descriptor size. A device reporting a larger wTotalLength than supplied descriptors causes an out-of-bounds read of the configuration buffer.
- CVE-2025-55100Critical
In USBX before version 6.4.3, the USB support module for Eclipse Foundation ThreadX, there was a potential out of bound read issue in _ux_host_class_audio10_sam_parse_func() when parsing a list of sampling frequencies.
- CVE-2025-55099Medium
In USBX before version 6.4.3, the USB support module for Eclipse Foundation ThreadX, there was a potential out-of-bounds read issue in _ux_host_class_audio_alternate_setting_locate() when parsing a descriptor with attacker-controlled frequency fields.
- CVE-2025-55098Medium
In USBX (USB support module for Eclipse Foundation ThreadX) before version 6.4.3, a potential out-of-bounds read exists in _ux_host_class_audio_device_type_get() when parsing a USB audio device descriptor.
- CVE-2025-55097Medium
In USBX before 6.4.3, the USB support module for Eclipse Foundation ThreadX, there was a potential out of bound read issue in _ux_host_class_audio_streaming_sampling_get() when parsing a descriptor of an USB streaming device.
- CVE-2025-55096Medium
In USBX before 6.4.3, the USB support module for Eclipse Foundation ThreadX, there is a potential out-of-bounds read issue in _ux_host_class_hid_report_descriptor_get() when parsing a descriptor of a USB HID device.
Original NVD description (English source)
The function _ux_host_class_storage_media_mount() is responsible for mounting partitions on a USB mass storage device. When it encounters an extended partition entry in the partition table, it recursively calls itself to mount the next logical partition. This recursion occurs in _ux_host_class_storage_partition_read(), which parses up to four partition entries. If an extended partition is found (with type UX_HOST_CLASS_STORAGE_PARTITION_EXTENDED or EXTENDED_LBA_MAPPED), the code invokes: _ux_host_class_storage_media_mount(storage, sector + _ux_utility_long_get(...)); There is no limit on the recursion depth or tracking of visited sectors. As a result, a malicious or malformed disk image can include cyclic or excessively deep chains of extended partitions, causing the function to recurse until stack overflow occurs.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS