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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.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2024-35865 is a Linux kernel SMB client flaw that could crash or disrupt an affected system. The issue is a potential use-after-free during SMB oplock break handling when sessions are being torn down. The public record rates it medium, with availability impact but no stated confidentiality or integrity impact.

Executive priority

Treat this as a routine but real availability risk. It is not described as remotely exploitable in the supplied sources, but affected Linux systems should be patched through normal kernel maintenance, with higher priority for shared systems allowing local users.

Technical view

The Linux kernel SMB client failed to skip sessions in SES_EXITING state inside smb2_is_valid_oplock_break(), creating a potential use-after-free. The CVSS vector is local, low complexity, low privileges, no user interaction, unchanged scope, and high availability impact.

Likely exposure

Exposure is most relevant to Linux systems running affected kernels with SMB/CIFS client functionality in use. The source bundle lists Linux as affected, but version data is commit-oriented and should be confirmed against distribution kernel advisories.

Exploitation context

The source bundle does not report active exploitation, and KEV status is false. CVSS indicates exploitation requires local low-privileged access and targets availability, not data theft or tampering. No public exploit details are provided in the supplied sources.

Researcher notes

Evidence points to a kernel SMB client lifecycle bug: sessions marked SES_EXITING must be skipped to avoid UAF. The sources provide upstream stable commits but no exploit narrative, affected CPEs, CWE, or distribution-specific package mapping.

Mitigation direction

  • Update to a kernel containing the cited stable fixes or your distribution's patched package.
  • Prioritize systems where local users can access Linux hosts using SMB/CIFS client functionality.
  • If SMB client use is unnecessary, reduce or disable that exposure until patched.
  • Track vendor kernel advisories because distribution backports may not match upstream version numbers.

Validation and detection

  • Inventory Linux kernel versions across servers, workstations, and appliances.
  • Identify systems mounting or using SMB/CIFS client functionality.
  • Compare installed kernels against distribution advisories for CVE-2024-35865.
  • Confirm the relevant upstream stable fix commit is included or backported.
  • Run regression checks for SMB/CIFS client workflows after kernel updates.
Prepared
Confidence
high
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
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

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.

1CVSS 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

1 official score

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
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

5.5Medium
CVSS 3.1 vector shape for CVE-2024-35865Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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