Security readout for executives and security teams
Plain-English summary
This Linux kernel issue can let a local privileged user crash a system by forcing EFI variable storage writable on firmware that cannot safely support runtime writes. It is an availability problem, not a remote takeover based on the provided sources.
Executive priority
Handle through normal kernel patch governance, with faster action for critical hosts where a local privileged crash would disrupt operations. There is no source-backed evidence of remote exploitation or active exploitation.
Technical view
efivarfs is mounted read-only when firmware lacks the SetVariable runtime callback. The vulnerable kernel path allowed remounting it read-write, then a write operation dereferenced a missing callback and caused a kernel NULL pointer crash. The fix denies non-read-only remounts in that condition.
Likely exposure
Exposure is limited to Linux systems using efivarfs on EFI firmware where runtime SetVariable is unsupported. The source lists Linux kernel versions beginning at 5.8 as affected and references stable kernel fixes. Distro backport status must be verified separately.
Exploitation context
The provided sources show a crash trigger and state KEV is false. They do not show active exploitation. Practical abuse appears local and privileged because remounting efivarfs read-write and writing EFI variables normally requires administrative capability.
Researcher notes
The bug is a missing permission/state check on remount, not an EFI variable parsing flaw. The critical condition is firmware without SetVariable support combined with an allowed read-write remount. Confirm exact affected ranges through kernel or distribution advisories.
Mitigation direction
- Update to a kernel containing the referenced stable efivarfs fix.
- Check distribution advisories for backported kernel packages.
- Keep efivarfs read-only on affected systems until patched.
- Restrict administrative access that can remount system filesystems.
- Prioritize systems where availability loss has operational impact.
Validation and detection
- Inventory Linux kernel versions on EFI-based systems.
- Confirm whether efivarfs is present under /sys/firmware/efi/efivars.
- Check vendor kernel changelogs for CVE-2023-52463 or the stable commit.
- Verify firmware reports whether runtime SetVariable is supported.
- Review logs for unexplained kernel oops or crashes involving efivarfs.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2023-52463 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/94c742324ed7e42c5bd6a9ed22e4ec6d764db4d8CVE reference, Linux
- https://git.kernel.org/stable/c/2aa141f8bc580f8f9811dfe4e0e6009812b73826CVE reference, Linux
- https://git.kernel.org/stable/c/d4a9aa7db574a0da64307729cc031fb68597aa8bCVE reference, Linux
- https://git.kernel.org/stable/c/0049fe7e4a85849bdd778cdb72e51a791ff3d737CVE reference, Linux
- https://git.kernel.org/stable/c/d4a714873db0866cc471521114eeac4a5072d548CVE reference, Linux
- https://git.kernel.org/stable/c/0e8d2444168dd519fea501599d150e62718ed2feCVE reference, Linux
- https://lists.debian.org/debian-lts-announce/2024/06/msg00016.htmlCVE reference, CVE · x_transferred
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.