Out-of-Bounds Read in Gnu Grub2 (CVE-2023-4693)
Summary
Vulnerability in Gnu Grub2 (CVE-2023-4693). Confidential information can be exposed externally.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2023-4693 has been found in Gnu Grub2.
Confidential information can be exposed externally. CVSS score: 5.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Gnu Grub2 CVE-2023-4693" on the vendor's site.
CVE-2023-4693 (Gnu Grub2) — CWE-125 / CVSS v3 5.3
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in Gnu Grub2.
Check the vendor advisory for the affected versions of Gnu Grub2.
Severity: Medium (CVSS 5.3/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Grub2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Grub2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Grub2を grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2023-4693 grub2 Fixed in: 2.06-3~deb11u6
References
- advisory access.redhat.com
- advisory bugzilla.redhat.com
- advisory seclists.org
- exploit dfir.ru
- mailing lists.gnu.org
- web access.redhat.com
- web access.redhat.com
- web lists.debian.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web security.gentoo.org
- web security.netapp.com