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CVE Record

CVE-2024-35865: smb: client: fix potential UAF in smb2_is_valid_oplock_break()

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in smb2_is_valid_oplock_break() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A Linux SMB client flaw can access memory after a session begins shutting down. The supplied record rates it critical at CVSS 9.8, indicating potentially severe confidentiality, integrity, and availability impact. Actual risk centers on affected kernels using SMB client functionality; the bundle provides no evidence of real-world exploitation.

Executive priority

Prioritize rapid exposure confirmation and patching for production systems connecting to SMB shares. The critical score justifies urgent handling, but there is no source-backed evidence of active exploitation. Verified systems not using the kernel SMB client have lower operational priority.

Technical view

smb2_is_valid_oplock_break() could inspect a session being torn down, creating a potential use-after-free. The correction skips sessions with status SES_EXITING. The CVSS vector describes network reachability, low complexity, no privileges, and no user interaction, but the bundle provides no reproducible trigger, demonstrated impact, or exploit.

Likely exposure

Potentially exposed assets are Linux systems running versions classified as affected and actively using the kernel SMB client, especially with untrusted SMB peers. The version data does not provide clear ranges and includes commit identifiers, so confirm applicability through distribution advisories and kernel backport records.

Exploitation context

KEV is false, and no supplied source claims active exploitation or provides a public proof of concept. This does not prove exploitation is impossible. The CVSS score represents scoring assumptions; the bundle does not establish reliable exploitation or observed business impact.

Researcher notes

The record describes a potential use-after-free and a narrow guard that ignores SES_EXITING sessions. It supplies no CWE, crash trace, exploitability analysis, or clear branch-to-fixed-version mapping. Treat impact claims beyond the CVSS vector as unverified and use the stable commits to map distribution backports.

Mitigation direction

  • Apply a supported distribution kernel update incorporating the referenced SES_EXITING session-skip fix.
  • Reboot into the updated kernel according to the Linux distribution's guidance.
  • Until updated, limit SMB client connections to trusted, necessary servers where operationally feasible.
  • Check vendor advisories for fixed package versions because the bundle's version mapping is ambiguous.

Validation and detection

  • Inventory running kernel versions and identify hosts using Linux kernel SMB client functionality.
  • Check distribution advisories and package changelogs for CVE-2024-35865 or the referenced commits.
  • Verify the remediated kernel is currently running, not merely installed.
  • Test required SMB workflows after updating and confirm normal session teardown behavior.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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CVE-2024-35865 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

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.

2CVSS vectors
3Timeline events
2ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We 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.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Linux
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2024-35865Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux7f48558e6489d032b1584b0cc9ac4bb11072c034, 7f48558e6489d032b1584b0cc9ac4bb11072c034, 7f48558e6489d032b1584b0cc9ac4bb11072c034, 7f48558e6489d032b1584b0cc9ac4bb11072c034, 7f48558e6489d032b1584b0cc9ac4bb11072c034, a67172a013953664b1dad03c648200c70b90506c, 3.12.48unaffected
LinuxLinux3.13, 0, 5.15.209, 6.1.85, 6.6.26, 6.8.5, 6.9affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.