Security readout for executives and security teams
Plain-English summary
This Linux kernel flaw can let a local user crash an affected system by hitting a bug in the XSK transmit path. It is an availability issue, not a data theft issue. Business urgency is highest for multi-user Linux hosts, container platforms, and systems where untrusted local users can run networking workloads.
Executive priority
Treat as a moderate availability risk. Patch during the next normal kernel maintenance cycle, sooner for shared or multi-tenant Linux infrastructure where local user activity can affect service uptime.
Technical view
CVE-2023-53240 is a NULL pointer dereference in Linux xsk Tx handling. The sendmsg path could mark a NAPI id before checking whether the network interface was up, leading to a kernel crash. The CVE maps to CWE-476 with CVSS 5.5, local attack vector, low complexity, low privileges, and high availability impact.
Likely exposure
Exposure is limited to affected Linux kernels where a local low-privileged user can exercise XSK/AF_XDP transmit behavior. The source bundle lists affected Linux versions including 5.18, 6.1.16, 6.2.3, and 6.3, but distro backport status is not provided.
Exploitation context
The source bundle provides a kernel crash trace and describes local triggering through sendmsg or poll paths. It does not cite public weaponization or active exploitation. KEV is false, so active exploitation should not be assumed from the provided evidence.
Researcher notes
The bug is a check-ordering issue: IFF_UP validation occurred too late in the sendmsg path, after NAPI id handling. The fix moves sanity checks into both __xsk_sendmsg and xsk_poll and refactors xsk_xmit for generic transmit handling.
Mitigation direction
- Update affected Linux kernels using vendor or Linux stable guidance.
- Confirm the applied kernel includes one of the referenced stable fixes.
- Prioritize shared systems where untrusted users can run local workloads.
- Review distro advisories because backported fixes may not match upstream version numbers.
Validation and detection
- Inventory Linux kernel versions across servers, containers hosts, and appliances.
- Check vendor changelogs for CVE-2023-53240 or referenced stable commits.
- Review crash logs for xsk_sendmsg, xsk_xmit, or NULL pointer dereference traces.
- Confirm whether AF_XDP/XSK workloads are present on exposed hosts.
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-2023-53240 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/cecc68559cd57fffb2be50685f262b9af2318e16CVE reference, Linux
- https://git.kernel.org/stable/c/ffe19750e68d0bb21e8110b398346eef20b156a7CVE reference, Linux
- https://git.kernel.org/stable/c/1596dae2f17ec5c6e8c8f0e3fec78c5ae55c1e0bCVE 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.