{"cve":"CVE-2023-34328","nvd":{"published":"2024-01-05T17:15:08.730","modified":"2026-06-17T06:03:24.240","status":"Modified","description":"[This CNA information record relates to multiple CVEs; the\ntext explains which aspects/vulnerabilities correspond to which CVE.]\n\nAMD CPUs since ~2014 have extensions to normal x86 debugging functionality.\nXen supports guests using these extensions.\n\nUnfortunately there are errors in Xen's handling of the guest state, leading\nto denials of service.\n\n 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of\n    a previous vCPUs debug mask state.\n\n 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT.\n    This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock\n    up the CPU entirely.","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":[],"references":["https://xenbits.xenproject.org/xsa/advisory-444.html","http://xenbits.xen.org/xsa/advisory-444.html","https://xenbits.xenproject.org/xsa/advisory-444.html"],"products":["xen:xen"],"source":"nvd","synced_at":"2026-10-19T21:43:38.875533635+00:00"},"epss":{"cve":"CVE-2023-34328","score":0.00245,"percentile":0.1584,"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."]}