Security readout for executives and security teams
Plain-English summary
CVE-2023-53399 is a Linux kernel ksmbd flaw where a missing share path can trigger a NULL pointer dereference. The practical impact is denial of service, not data theft or code execution based on the supplied sources. It matters most for Linux systems using the in-kernel SMB server.
Executive priority
Treat as a moderate availability risk. It is not presented as data compromise or remote code execution, but SMB file-service outages can be operationally disruptive. Prioritize internet-facing or business-critical file-sharing hosts after confirming ksmbd use.
Technical view
The bug is in ksmbd's smb2_get_info_filesystem() path. If the share object has a NULL path, dereferencing share->path can crash kernel execution. The CVSS vector is local, low complexity, low privileges, no user interaction, unchanged scope, and high availability impact.
Likely exposure
Exposure is most likely on Linux hosts where ksmbd is enabled or packaged into deployed kernels, especially SMB file-sharing systems. The supplied affected data names Linux kernel versions and stable commit ranges, but does not identify distributions, appliances, or default configurations.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. The provided CVSS vector indicates local access with low privileges is required. No exploit maturity, public exploit, or remote attack evidence is included in the supplied material.
Researcher notes
Evidence supports a CWE-476 NULL pointer dereference in Linux ksmbd with high availability impact. The affected-version metadata is limited and somewhat terse, so distribution-level impact and fixed package mapping require vendor advisory confirmation.
Mitigation direction
- Update to a Linux kernel or vendor package containing the referenced stable ksmbd fix.
- Prioritize systems running ksmbd or providing SMB service from the Linux kernel.
- If ksmbd is unnecessary, disable it according to vendor guidance.
- Check distribution advisories for exact fixed package versions before change windows.
Validation and detection
- Inventory Linux systems using ksmbd or kernel SMB server functionality.
- Compare deployed kernel versions against vendor advisories and the referenced stable commits.
- Confirm whether SMB service exposure depends on ksmbd rather than Samba user-space services.
- Review crash logs for ksmbd-related NULL dereference events.
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.
CWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2023-53399 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
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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/227eb2689b44d0d60da3839b146983e73435924cCVE reference, Linux
- https://git.kernel.org/stable/c/a70751dd7b60eab025e97e19b6b2477c6eaf2bbbCVE reference, Linux
- https://git.kernel.org/stable/c/b35f6c031b87d9e51f141ff6de0ea59756a8e313CVE reference, Linux
- https://git.kernel.org/stable/c/1636e09779f83e10e6ed57d91ef94abcefdd206bCVE reference, Linux
- https://git.kernel.org/stable/c/3ac00a2ab69b34189942afa9e862d5170cdcb018CVE reference, Linux
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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.