Security readout for executives and security teams
Plain-English summary
A Linux NFS server kernel component can mishandle the lifetime of an export object during status display. A local, low-privileged user may trigger a use-after-free warning. The supplied record rates potential confidentiality, integrity, and availability impact as high, but provides no evidence of successful compromise or active exploitation.
Executive priority
Prioritize expedited remediation on NFS servers shared by users or untrusted workloads. Treat isolated systems without nfsd as lower urgency after confirming component usage. There is high theoretical impact but no supplied evidence of exploitation, so this warrants controlled patching rather than emergency incident response by itself.
Technical view
Within nfsd, e_show relied on RCU to prevent exp from being freed, but RCU did not ensure its reference count remained above zero. A subsequent exp_get could add a reference to an inactive object, producing a refcount use-after-free warning. The kernel fix uses cache_get_rcu to keep the export active.
Likely exposure
Exposure is most relevant to affected Linux systems using the nfsd component, particularly multi-user or otherwise locally accessible hosts. The supplied affected-version data is ambiguous, so vulnerability managers should confirm fixed kernel builds through their distribution rather than relying solely on upstream version numbers.
Exploitation context
The CVSS 3.1 vector is 7.8 and requires local access with low privileges; no user interaction is required. The bundle reports no KEV listing, and none of the supplied sources documents active exploitation, a public exploit, remote reachability, or demonstrated data compromise.
Researcher notes
The reproduced trace demonstrates a refcount addition on zero in e_show, classified as CWE-416. It does not establish reliable memory corruption, privilege escalation, or code execution. Multiple Linux stable commits indicate backports, while Debian LTS advisories provide downstream remediation context. Exact affected and fixed release boundaries remain unclear in the supplied version data.
Mitigation direction
- Install a distribution-supported kernel update containing the CVE-2024-56558 fix.
- Reboot into the updated kernel after following the distribution's deployment guidance.
- Disable nfsd where NFS server functionality is unnecessary, subject to operational approval.
- Restrict local account and workload access until affected systems are updated.
Validation and detection
- Inventory running kernel builds and identify systems providing NFS server functionality.
- Confirm each distribution package includes its vendor's CVE-2024-56558 correction.
- Verify systems booted into the corrected kernel after maintenance.
- Review kernel logs for refcount use-after-free warnings involving e_show or nfsd.
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 lookupCVE-2024-56558 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
2 official scoresWe 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:H1.85.9LinuxCVSS: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
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/e2fa0d0e327279a8defb87b263cd0bf288fd9261CVE reference, Linux
- https://git.kernel.org/stable/c/7fd29d284b55c2274f7a748e6c5f25b4758b8da5CVE reference, Linux
- https://git.kernel.org/stable/c/6cefcadd34e3c71c81ea64b899a0daa86314a51aCVE reference, Linux
- https://git.kernel.org/stable/c/7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ecCVE reference, Linux
- https://git.kernel.org/stable/c/1cecfdbc6bfc89c516d286884c7f29267b95de2bCVE reference, Linux
- https://git.kernel.org/stable/c/7365d1f8de63cffdbbaa2287ce0205438e1a922fCVE reference, Linux
- https://git.kernel.org/stable/c/be8f982c369c965faffa198b46060f8853e0f1f0CVE reference, Linux
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.htmlCVE reference, CVE
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.htmlCVE reference, CVE
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.