Security readout for executives and security teams
Plain-English summary
A flaw in the Linux kernel’s nftables firewall subsystem could let a user who already has limited local access gain full system privileges. Successful exploitation could expose data, alter systems, or disrupt services. The supplied record rates it high severity at CVSS 7.8.
Executive priority
Prioritize remediation in the normal high-severity patch cycle, accelerating shared infrastructure, build systems, and hosts running untrusted workloads. This is not remotely exploitable according to the supplied CVSS vector, but successful local escalation could yield complete control of an affected host.
Technical view
A race between nf_tables netlink transactions and nft_set element garbage collection can underflow a reference counter, producing a use-after-free condition. The issue requires local access and low privileges, needs no user interaction, and may compromise confidentiality, integrity, and availability without changing security scope.
Likely exposure
Exposure is limited to Linux systems running a vulnerable kernel with the nf_tables component reachable by a low-privileged local user. The supplied affected-version data lists 4.20, 5.5, 5.11, 5.16, and 6.2, but does not provide reliable distribution-specific package boundaries; verify each vendor kernel build.
Exploitation context
The CVSS vector indicates local, low-complexity exploitation by a low-privileged user without user interaction. The supplied bundle does not identify public exploitation, and the CVE is not listed as KEV. Treat systems permitting untrusted local or container workloads as higher priority, while avoiding assumptions about exploit availability.
Researcher notes
The central defect is CWE-416 caused by reference-counter underflow during a control-plane and garbage-collection race. The upstream recommendation is to upgrade beyond commit 3e91b0ebd994635df2346353322ac51ce84ce6d8. The source bundle lacks authoritative per-distribution version ranges and does not establish active exploitation, so package-level conclusions require vendor advisory confirmation.
Mitigation direction
- Upgrade to a vendor-supported kernel containing or superseding commit 3e91b0ebd994635df2346353322ac51ce84ce6d8.
- Consult the Linux distribution’s security advisory for the exact fixed package and reboot requirements.
- Prioritize shared hosts and systems where untrusted users or workloads can obtain local access.
- Restrict unnecessary local accounts and nftables-related access while patching is pending.
Validation and detection
- Inventory running kernel versions and distribution package revisions across Linux systems.
- Compare each installed kernel against its distribution’s CVE-2023-4244 advisory and fixed package.
- Confirm the updated kernel is installed and active after any required reboot.
- Verify nftables exposure and identify hosts allowing untrusted local users or workloads.
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-416: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2023-4244 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
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.
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:H/I:H/A:H1.85.9GoogleVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3e91b0ebd994635df2346353322ac51ce84ce6d8CVE reference, Google · patch
- https://kernel.dance/3e91b0ebd994635df2346353322ac51ce84ce6d8CVE reference, Google
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlCVE reference, Google
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlCVE reference, Google
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.