Security readout for executives and security teams
Plain-English summary
CVE-2024-39463 is a Linux kernel 9p filesystem use-after-free. A local user with low privileges may be able to trigger unsafe memory access when one thread looks up a 9p file identifier while another removes it. The CVSS score is high because successful exploitation could affect confidentiality, integrity, and availability.
Executive priority
Handle in the normal high-severity kernel patch cycle, with faster action for multi-user, shared, or virtualized environments where local users are less trusted. There is no source-backed evidence of active exploitation, but kernel memory corruption can become a serious privilege boundary risk.
Technical view
The bug is missing d_lock protection around a dentry d_fsdata fid list in fs/9p. v9fs_remove can explicitly release dentry data while another path, such as getattr/statx through v9fs_fid_find, still obtains a fid reference, creating a CWE-416 use-after-free. Kernel stable commits add locking and move the hlist before dropping fid references.
Likely exposure
Exposure is most likely on Linux systems running affected kernel versions where the 9p filesystem code is present and usable. The source bundle identifies Linux kernel versions beginning with 5.11 and stable branch fixes, but operators should map their distribution package versions to upstream fixes.
Exploitation context
The CVSS vector is local, low complexity, low privileges, and no user interaction. The bundle does not identify remote exploitation or confirmed in-the-wild exploitation, and KEV is false. Treat it as a local kernel memory-safety issue requiring practical access to a vulnerable system.
Researcher notes
The vulnerable race involves dentry fid-list access without d_lock while v9fs_remove explicitly releases dentry data. The public description includes KASAN-style traces for p9_fid_get and p9_fid_destroy paths. Analysis should focus on kernel version mapping, 9p reachability, and vendor backports rather than assuming all Linux hosts are equally exposed.
Mitigation direction
- Update to a kernel containing the referenced stable fixes or your distribution backport.
- Prioritize systems where untrusted local users can access 9p functionality.
- Check vendor advisories for distribution-specific fixed package versions.
- Reduce unnecessary 9p exposure where operationally possible until patched.
- Do not deploy directly from upstream assumptions; confirm packaged kernel status.
Validation and detection
- Inventory Linux kernel versions across hosts and images.
- Identify systems where 9p filesystem support is enabled or mounted.
- Compare kernel packages against vendor advisories and upstream stable fix references.
- Review vulnerability scanner findings for CVE-2024-39463 package mapping accuracy.
- After patching, verify the running kernel changed, not only the installed package.
Public sources used
- CVE Program
- CVE List V5
- Linux stable commit 3bb6763a8319170c2d41c4232c8e7e4c37dcacfb
- Linux stable commit cb299cdba09f46f090b843d78ba26b667d50a456
- Linux stable commit f0c5c944c6d8614c19e6e9a97fd2011dcd30e8f5
- Linux stable commit fe17ebf22feb4ad7094d597526d558a49aac92b4
- Linux stable commit c898afdc15645efb555acb6d85b484eb40a45409
- Zero Day Initiative ZDI-24-1194
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 lookupCVE-2024-39463 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.
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:H/I:H/A:H1.85.9CISA-ADPVulnerability 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/stable/c/3bb6763a8319170c2d41c4232c8e7e4c37dcacfbCVE reference, Linux
- https://git.kernel.org/stable/c/cb299cdba09f46f090b843d78ba26b667d50a456CVE reference, Linux
- https://git.kernel.org/stable/c/f0c5c944c6d8614c19e6e9a97fd2011dcd30e8f5CVE reference, Linux
- https://git.kernel.org/stable/c/fe17ebf22feb4ad7094d597526d558a49aac92b4CVE reference, Linux
- https://git.kernel.org/stable/c/c898afdc15645efb555acb6d85b484eb40a45409CVE reference, Linux
- https://www.zerodayinitiative.com/advisories/ZDI-24-1194/CVE 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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.