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CVE Record

CVE-2023-52439: uio: Fix use-after-free in uio_open

In the Linux kernel, the following vulnerability has been resolved: uio: Fix use-after-free in uio_open core-1 core-2 ------------------------------------------------------- uio_unregister_device uio_open idev = idr_find() device_unregister(&idev->dev) put_device(&idev->dev) uio_device_release get_device(&idev->dev) kfree(idev) uio_free_minor(minor) uio_release put_device(&idev->dev) kfree(idev) ------------------------------------------------------- In the core-1 uio_unregister_device(), the device_unregister will kfree idev when the idev->dev kobject ref is 1. But after core-1 device_unregister, put_device and before doing kfree, the core-2 may get_device. Then: 1. After core-1 kfree idev, the core-2 will do use-after-free for idev. 2. When core-2 do uio_release and put_device, the idev will be double freed. To address this issue, we can get idev atomic & inc idev reference with minor_lock.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This Linux kernel UIO flaw can corrupt kernel memory when opening a device races with its removal. A low-privileged local user may trigger use-after-free and double-free conditions, potentially causing a system crash or broader compromise. Practical risk depends on whether UIO is present and accessible to that user.

Executive priority

Treat this as high priority on affected multi-user Linux systems using UIO. It is not directly network-reachable according to the supplied CVSS vector, so prioritize by UIO usage and local-user exposure. Apply vendor-supported kernel updates promptly, accelerating remediation where untrusted or low-privileged users share the host.

Technical view

uio_open can obtain an idev pointer while uio_unregister_device is releasing the same object. Because the reference was not acquired atomically under minor_lock, the object may be freed before get_device, causing use-after-free and a subsequent double free during release. The cited fix acquires the device and increments its reference while holding the lock.

Likely exposure

Exposure is local rather than directly network-based. Highest concern applies to affected Linux systems using UIO where low-privileged users can access relevant device nodes. The bundled version entries lack clear range semantics, so distribution package and backport status must be checked before declaring a system vulnerable or fixed.

Exploitation context

The CVSS 3.1 score is 7.8 with local access, low privileges, low complexity, and no user interaction. The bundle marks KEV false and supplies no cited evidence of active exploitation or public exploit availability. Confidentiality, integrity, and availability impacts are rated high, but successful compromise is not demonstrated in the supplied evidence.

Researcher notes

The bundle provides no CWE, reproduction, or exploitation evidence. Its flattened version entries mix hashes and versions without clear range semantics. Validate vendor packages and backports rather than inferring status solely from that list. Impact beyond crashes and memory corruption remains potential, based on the supplied CVSS assessment rather than demonstrated exploitation.

Mitigation direction

  • Update affected kernels to a vendor-supported release containing the applicable upstream UIO fix.
  • Consult distribution advisories because the bundled affected-version data is insufficiently clear for package-level decisions.
  • Prioritize systems using UIO and allowing low-privileged users to access relevant device nodes.
  • If patching is delayed, restrict untrusted local access and UIO device-node permissions after operational review.

Validation and detection

  • Inventory running kernel versions, distribution package revisions, and hosts using the UIO subsystem.
  • Confirm the running kernel contains a cited stable fix or a documented vendor backport.
  • Review permissions and ownership for UIO device nodes available to low-privileged users.
  • After updating and rebooting, verify each host is running the intended remediated kernel.
Prepared
Confidence
medium
Sources
12

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

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CVE-2023-52439 mapping review

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Vulnerability profileCVE Program record
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

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
12Source 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
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2023-52439Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9, 13af019c87f2d90e663742cb1a819834048842ae, 4.14.100unaffected
LinuxLinux4.18, 0, 4.19.306, 5.4.268, 5.10.209, 5.15.148, 6.1.74, 6.6.13, 6.7.1, 6.8affected
Weakness

CWE details

No CWE listed

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