{"cve":"CVE-2025-21689","nvd":{"published":"2025-02-10T16:15:38.447","modified":"2026-06-17T08:44:01.713","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()\n\nThis patch addresses a null-ptr-deref in qt2_process_read_urb() due to\nan incorrect bounds check in the following:\n\n       if (newport > serial->num_ports) {\n               dev_err(&port->dev,\n                       \"%s - port change to invalid port: %i\\n\",\n                       __func__, newport);\n               break;\n       }\n\nThe condition doesn't account for the valid range of the serial->port\nbuffer, which is from 0 to serial->num_ports - 1. When newport is equal\nto serial->num_ports, the assignment of \"port\" in the\nfollowing code is out-of-bounds and NULL:\n\n       serial_priv->current_port = newport;\n       port = serial->port[serial_priv->current_port];\n\nThe fix checks if newport is greater than or equal to serial->num_ports\nindicating it is out-of-bounds.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/4b9b41fabcd38990f69ef0cee9c631d954a2b530","https://git.kernel.org/stable/c/575a5adf48b06a2980c9eeffedf699ed5534fade","https://git.kernel.org/stable/c/6068dcff7f19e9fa6fa23ee03453ad6a40fa4efe","https://git.kernel.org/stable/c/6377838560c03b36e1153a42ef727533def9b68f","https://git.kernel.org/stable/c/8542b33622571f54dfc2a267fce378b6e3840b8b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:18.731010617+00:00"},"epss":{"cve":"CVE-2025-21689","score":0.00226,"percentile":0.13317,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}