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CVE Record

CVE-2024-38618: ALSA: timer: Set lower bound of start tick time

In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: Set lower bound of start tick time Currently ALSA timer doesn't have the lower limit of the start tick time, and it allows a very small size, e.g. 1 tick with 1ns resolution for hrtimer. Such a situation may lead to an unexpected RCU stall, where the callback repeatedly queuing the expire update, as reported by fuzzer. This patch introduces a sanity check of the timer start tick time, so that the system returns an error when a too small start size is set. As of this patch, the lower limit is hard-coded to 100us, which is small enough but can still work somehow.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2024-38618 is a Linux kernel availability issue in the ALSA timer component. Extremely small timer start values can cause repeated timer activity and an unexpected RCU stall, potentially degrading or disrupting system availability. The public record rates it medium severity, and there is no provided evidence of active exploitation.

Executive priority

Treat as routine-to-prioritized kernel maintenance, not an emergency. Focus on systems where availability is critical or untrusted users can reach kernel audio timer functionality. Bundle with scheduled kernel patch cycles unless local risk conditions justify faster action.

Technical view

The ALSA timer lacked a lower bound for start tick time, allowing very small values such as one tick at nanosecond resolution. Kernel maintainers resolved this by adding a sanity check and hard-coding a 100 microsecond lower limit. The CVSS 3.1 score is 5.3, with availability impact only.

Likely exposure

Linux systems running affected kernel versions listed in the CVE data may be exposed. The bundle identifies affected lines including 2.6.29, 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.93, 6.6.33, 6.9.3, and 6.10. Distribution backports may change exposure.

Exploitation context

The issue was reported by a fuzzer. The source bundle does not indicate public exploit availability or active exploitation, and KEV status is false. Practical risk is primarily denial of service or availability degradation rather than data theft or privilege escalation.

Researcher notes

Evidence is limited to the kernel fix description, CVE metadata, stable commit references, and a Debian LTS announcement. The CVE text describes an RCU stall caused by too-small timer starts. No CWE, exploit status, or detailed affected distribution matrix is provided in the bundle.

Mitigation direction

  • Update to a kernel version containing the referenced stable fixes.
  • Apply distribution kernel updates, including relevant Debian LTS guidance where applicable.
  • If using vendor kernels, confirm backport status with the vendor advisory.
  • Prioritize shared or untrusted multi-user Linux environments.

Validation and detection

  • Inventory Linux kernel versions across servers, endpoints, appliances, and containers using host kernels.
  • Compare installed kernels against vendor advisories and fixed stable commits.
  • Verify ALSA timer exposure where untrusted local or application access exists.
  • Confirm updated kernels are running after maintenance and reboot processes.
Prepared
Confidence
high
Sources
11

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-2024-38618 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (3.1)
Known Exploited
No
Published

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

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
10Source 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
5.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.3Medium
CVSS 3.1 vector shape for CVE-2024-38618Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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
LinuxLinuxbbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2, bbaf5e97337287479eb78dbc3822d9560bbfd2e2unaffected
LinuxLinux2.6.29, 0, 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.93, 6.6.33, 6.9.3, 6.10affected
Weakness

CWE details

No CWE listed

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