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CVE Record

CVE-2024-35827: io_uring/net: fix overflow check in io_recvmsg_mshot_prep()

In the Linux kernel, the following vulnerability has been resolved: io_uring/net: fix overflow check in io_recvmsg_mshot_prep() The "controllen" variable is type size_t (unsigned long). Casting it to int could lead to an integer underflow. The check_add_overflow() function considers the type of the destination which is type int. If we add two positive values and the result cannot fit in an integer then that's counted as an overflow. However, if we cast "controllen" to an int and it turns negative, then negative values *can* fit into an int type so there is no overflow. Good: 100 + (unsigned long)-4 = 96 <-- overflow Bad: 100 + (int)-4 = 96 <-- no overflow I deleted the cast of the sizeof() as well. That's not a bug but the cast is unnecessary.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A flaw in Linux io_uring network message handling can let a low-privileged local user bypass an integer overflow check. The CVSS assessment indicates possible serious confidentiality, integrity, and availability impact. It is not described as remotely exploitable, and the supplied sources do not establish the precise failure or exploitation outcome.

Executive priority

Treat this as expedited high-priority patching for exposed multi-user Linux systems. Its local-access requirement reduces immediate internet-facing urgency, but low required privileges and the assessed system-wide impact make prolonged exposure undesirable. Prioritize systems permitting untrusted users, containers, or shared workloads.

Technical view

In io_recvmsg_mshot_prep(), an unsigned size_t controllen value was cast to int before check_add_overflow(). A sufficiently large value could become negative, allowing an invalid addition to appear representable and bypass overflow detection. Linux stable commits remove the problematic cast. The source bundle does not document the subsequent memory-safety primitive.

Likely exposure

Exposure is limited to Linux systems running affected kernels where a low-privileged local actor can reach the vulnerable io_uring receive-message path. The affected data lists versions from 6.0 and several later branch versions, but its formatting is insufficient to determine every vulnerable distribution package reliably.

Exploitation context

The CVSS vector describes local access, low privileges, low complexity, and no user interaction. The bundle marks this CVE as absent from KEV and provides no cited evidence of active exploitation. Absence from KEV does not prove exploitation has never occurred.

Researcher notes

The affected-version data is unusually formatted, including repeated commit identifiers marked unaffected and a mixed version list marked affected. Do not infer exact distribution exposure solely from those entries. Establish branch-specific introduction and correction boundaries using the cited stable commits and vendor package advisories. No CWE or demonstrated exploit primitive is supplied.

Mitigation direction

  • Apply vendor-supported kernel updates incorporating the applicable Linux stable fix.
  • Prioritize multi-user systems and workloads where untrusted local users can access io_uring.
  • If updates are unavailable, consult distributor guidance for supported temporary mitigations.
  • Reboot into the updated kernel and retire vulnerable kernel images according to change policy.

Validation and detection

  • Inventory running kernel versions and confirm whether io_uring is available.
  • Compare each kernel package against Linux stable fix commits and distributor advisories.
  • Verify updated kernels are running after reboot, not merely installed.
  • Re-scan hosts and document exceptions where patch status remains uncertain.
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-2024-35827 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
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
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-2024-35827Attack 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

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux9b0fc3c054ff2eb13753104884f1045b5bb3a627, 9b0fc3c054ff2eb13753104884f1045b5bb3a627, 9b0fc3c054ff2eb13753104884f1045b5bb3a627, 9b0fc3c054ff2eb13753104884f1045b5bb3a627, 9b0fc3c054ff2eb13753104884f1045b5bb3a627unaffected
LinuxLinux6.0, 0, 6.1.83, 6.6.23, 6.7.11, 6.8.2, 6.9affected
Weakness

CWE details

No CWE listed

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