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CVE Record

CVE-2023-53794: cifs: fix session state check in reconnect to avoid use-after-free issue

In the Linux kernel, the following vulnerability has been resolved: cifs: fix session state check in reconnect to avoid use-after-free issue Don't collect exiting session in smb2_reconnect_server(), because it will be released soon. Note that the exiting session will stay in server->smb_ses_list until it complete the cifs_free_ipc() and logoff() and then delete itself from the list.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

A Linux kernel CIFS/SMB client reconnect bug can leave code touching a session that is already exiting, creating a use-after-free condition. The business risk depends on whether affected kernels are used and whether CIFS/SMB mounts are active. No CVSS score or active exploitation evidence is provided in the source bundle.

Executive priority

Prioritize normal kernel patch management, with faster handling for file-sharing clients that rely on CIFS/SMB. Current sources do not justify emergency response, but incomplete severity data means exposure should still be confirmed.

Technical view

The issue is in cifs smb2_reconnect_server(). The fix avoids collecting sessions marked as exiting because they remain on server->smb_ses_list while cifs_free_ipc() and logoff() complete, then remove themselves. Using such a session during reconnect can cause a use-after-free.

Likely exposure

Most relevant exposure is Linux systems running affected kernel builds with CIFS/SMB client functionality in use. The bundle lists Linux kernel affected version markers including 4.7, 0, 6.1.47, 6.4.12, and 6.5, but distro backports may change practical exposure.

Exploitation context

The source bundle does not identify active exploitation, public exploit activity, attack prerequisites, or impact beyond a kernel use-after-free. KEV is false. Treat exploitability as unproven from these sources, not impossible.

Researcher notes

Focus review on CIFS reconnect session lifecycle and state handling. The key condition is an exiting session remaining in server->smb_ses_list until cleanup and logoff finish. The bundle does not include crash traces, CVSS, exploitability analysis, or complete distro impact.

Mitigation direction

  • Update to a vendor-supported kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for backported fixes matching CVE-2023-53794.
  • Prioritize systems that use CIFS/SMB mounts or automated reconnect behavior.
  • If no update is available, follow vendor guidance for temporary risk reduction.

Validation and detection

  • Inventory Linux kernel versions on systems that use CIFS/SMB mounts.
  • Confirm whether deployed kernels include one of the referenced stable commits or distro backports.
  • Review mount and workload configuration for active CIFS/SMB client usage.
  • Track the CVE record and kernel stable references for updated severity or affected-version details.
Prepared
Confidence
medium
Sources
5

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-2023-53794 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
0ADP providers
4Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux4fcd1813e6404dd4420c7d12fb483f9320f0bf93, 4fcd1813e6404dd4420c7d12fb483f9320f0bf93, 4fcd1813e6404dd4420c7d12fb483f9320f0bf93, 655e0c067f0e02ece03fd0591dabe3db2ae27552, 875cc09c0767a4ac06b57af383709657f98b3ea1, 599fe1409085059ba12a2c3897c853be9fa9e7cf, 2e4378ee60049b752c9dce16f62ce6fbd11b379a, 59b520454b323ec43b2ae757217332cea33091e0, e20c888e2b3576e5f498c167729d274ef60b86f8, 4ce7aa4e44d88ce64ea8ae2337b8910f3670b0ba, 419fad68e4c4135ff9859e9214dd6cf954413ca1, 3.10.103, 3.12.63, 3.14.74, 3.16.37, 3.18.37, 4.1.28, 4.4.16, 4.6.5unaffected
LinuxLinux4.7, 0, 6.1.47, 6.4.12, 6.5affected
Weakness

CWE details

No CWE listed

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