{"cve":"CVE-2021-47008","nvd":{"published":"2024-02-28T09:15:38.560","modified":"2026-06-17T04:16:09.973","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Make sure GHCB is mapped before updating\n\nAccess to the GHCB is mainly in the VMGEXIT path and it is known that the\nGHCB will be mapped. But there are two paths where it is possible the GHCB\nmight not be mapped.\n\nThe sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform\nthe caller of the AP Reset Hold NAE event that a SIPI has been delivered.\nHowever, if a SIPI is performed without a corresponding AP Reset Hold,\nthen the GHCB might not be mapped (depending on the previous VMEXIT),\nwhich will result in a NULL pointer dereference.\n\nThe svm_complete_emulated_msr() routine will update the GHCB to inform\nthe caller of a RDMSR/WRMSR operation about any errors. While it is likely\nthat the GHCB will be mapped in this situation, add a safe guard\nin this path to be certain a NULL pointer dereference is not encountered.","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/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad","https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47","https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e","https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad","https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2021-47008","score":0.00236,"percentile":0.14579,"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."]}