CVE-2021-3839Network attack vector

Application crash via unchecked inflight queue count

Published Aug 23, 2022 · Updated Aug 3, 2024

Out-of-bounds access in the DPDK vhost library before 22.03 allows remote attackers to crash a linked application via an inflight message. vhost_user_set_inflight_fd() uses an unchecked num_queues value to index the virtqueue array and write inflight metadata beyond its bounds. The target must expose the vhost-user message path through software linked with the library; successful exploitation interrupts that application.

CVSS severity7.5
High
EPSS probability1.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in the DPDK vhost library before 22.03 allows remote attackers to crash a linked application via an inflight message. vhost_user_set_inflight_fd() uses an unchecked num_queues value to index the virtqueue array and write inflight metadata beyond its bounds. The target must expose the vhost-user message path through software linked with the library; successful exploitation interrupts that application.

The record

CVE
CVE-2021-3839
Published
Aug 23, 2022
Updated
Aug 3, 2024
Vendor
DPDK Project
Product
DPDK
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in dpdk v22.03

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

DPDK Project · DPDKversion=Fixed in dpdk v22.03

Published CVSS scores

7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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