# CVE-2023-4693: Grub2: out-of-bounds read at fs/ntfs.c Status: published. Published: 2023-10-25. Updated: 2026-11-02. An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations. A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting a high Confidentiality risk. ## Remediation No remediation reported in collected sources ## Affected products and versions - Red Hat / Red Hat Enterprise Linux 8 (grub2): ≥ 1:2.02-156.el8; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 9 (grub2): ≥ 1:2.06-77.el9; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 7 (grub2): Version range not reported. Source: CNA: redhat ## NVD configuration conditions Affected CPE matches depend on the following AND/OR and negation conditions: ```json [ { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.12", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" }, { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" } ] ``` ## Severity and prioritization - CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N; source: CNA: redhat - CVSS 3.1: 4.6 (medium); CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N; source: NVD: nvd@nist.gov - CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N; source: NVD: secalert@redhat.com - CISA KEV: No listing in collected sources - EPSS: 0.49% as of 2026-11-02; percentile 42.04% - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-125 ## Exploit evidence - exploit: https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (secalert@redhat.com) - exploit: https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (af854a3a-2127-422b-91ae-364da2661108) ## References - https://access.redhat.com/errata/RHSA-2024:2456 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2024:3184 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/security/cve/CVE-2023-4693 (CNA: redhat; vdb-entry, x_refsource_REDHAT) - https://bugzilla.redhat.com/show_bug.cgi?id=2238343 (CNA: redhat; issue-tracking, x_refsource_REDHAT) - https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (CNA: redhat) - https://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html (CNA: redhat) - https://seclists.org/oss-sec/2023/q4/37 (CNA: redhat) - https://access.redhat.com/errata/RHSA-2024:2456 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/errata/RHSA-2024:3184 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/security/cve/CVE-2023-4693 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred) - https://bugzilla.redhat.com/show_bug.cgi?id=2238343 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred) - https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FUU42E7CPYLATXOYVYNW6YTXXULAOV6L/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OIRJ5UZRXX2KLR4IKBJEQUNGOCXMMDLY/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PERFILCHFEUGG3OAMC6W55P6DDIBZK4Q/ (ADP: CVE; x_transferred) - https://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html (ADP: CVE; x_transferred) - https://seclists.org/oss-sec/2023/q4/37 (ADP: CVE; x_transferred) - https://security.gentoo.org/glsa/202311-14 (ADP: CVE; x_transferred) - https://security.netapp.com/advisory/ntap-20231208-0002/ (ADP: CVE; x_transferred) - https://lists.debian.org/debian-lts-announce/2023/10/msg00007.html (ADP: CVE) - https://access.redhat.com/errata/RHSA-2024:2456 (secalert@redhat.com) - https://access.redhat.com/errata/RHSA-2024:3184 (secalert@redhat.com) - https://access.redhat.com/security/cve/CVE-2023-4693 (secalert@redhat.com; Third Party Advisory) - https://bugzilla.redhat.com/show_bug.cgi?id=2238343 (secalert@redhat.com; Issue Tracking, Third Party Advisory) - https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (secalert@redhat.com; Exploit, Third Party Advisory) - https://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html (secalert@redhat.com; Mailing List) - https://seclists.org/oss-sec/2023/q4/37 (secalert@redhat.com; Mailing List, Third Party Advisory) - https://access.redhat.com/errata/RHSA-2024:2456 (af854a3a-2127-422b-91ae-364da2661108) - https://access.redhat.com/errata/RHSA-2024:3184 (af854a3a-2127-422b-91ae-364da2661108) - https://access.redhat.com/security/cve/CVE-2023-4693 (af854a3a-2127-422b-91ae-364da2661108; Third Party Advisory) - https://bugzilla.redhat.com/show_bug.cgi?id=2238343 (af854a3a-2127-422b-91ae-364da2661108; Issue Tracking, Third Party Advisory) - https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/ (af854a3a-2127-422b-91ae-364da2661108; Exploit, Third Party Advisory) - https://lists.debian.org/debian-lts-announce/2023/10/msg00007.html (af854a3a-2127-422b-91ae-364da2661108) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FUU42E7CPYLATXOYVYNW6YTXXULAOV6L/ (af854a3a-2127-422b-91ae-364da2661108) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OIRJ5UZRXX2KLR4IKBJEQUNGOCXMMDLY/ (af854a3a-2127-422b-91ae-364da2661108) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PERFILCHFEUGG3OAMC6W55P6DDIBZK4Q/ (af854a3a-2127-422b-91ae-364da2661108) - https://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html (af854a3a-2127-422b-91ae-364da2661108; Mailing List) - https://seclists.org/oss-sec/2023/q4/37 (af854a3a-2127-422b-91ae-364da2661108; Mailing List, Third Party Advisory) - https://security.gentoo.org/glsa/202311-14 (af854a3a-2127-422b-91ae-364da2661108) - https://security.netapp.com/advisory/ntap-20231208-0002/ (af854a3a-2127-422b-91ae-364da2661108) ## Provenance - CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-4693; retrieved 2026-11-02; source updated 2026-11-02 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4693; retrieved 2026-11-03; source updated 2026-11-02 - FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-4693; retrieved 2026-11-02; source updated Not reported Revision: c7567486b766dae73e20de2ae77a219ea7c703ef96b2ac0a87061e39f22ee878 Canonical: https://y2.dev/cve/CVE-2023-4693 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end. - WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers. - Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}. - Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer . Setup: https://y2.dev/docs/api/create-key. - x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402. - OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json. Collected public records only. Check source status for coverage and freshness.