CVE-2025-54351Network attack vector

Memory corruption via MSG_TRUNC length miscalculation

Published Aug 3, 2025 · Updated Aug 4, 2025

Buffer overflow in ESnet iperf3 before 3.19.1 allows remote attackers to corrupt memory through UDP tests using --skip-rx-copy. The Nrecv and Nrecv_no_select loops treat recv's MSG_TRUNC return as bytes copied, subtract the full datagram length, and advance the buffer pointer past its allocation. The condition is reachable only when a UDP receiver uses --skip-rx-copy; memory corruption can crash the process or alter its execution.

CVSS severity8.9
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in ESnet iperf3 before 3.19.1 allows remote attackers to corrupt memory through UDP tests using --skip-rx-copy. The Nrecv and Nrecv_no_select loops treat recv's MSG_TRUNC return as bytes copied, subtract the full datagram length, and advance the buffer pointer past its allocation. The condition is reachable only when a UDP receiver uses --skip-rx-copy; memory corruption can crash the process or alter its execution.

The record

CVE
CVE-2025-54351
Published
Aug 3, 2025
Updated
Aug 4, 2025
Vendor
ESnet
Product
iperf3
Classifications
CWE-420, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2025Record 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=0 <3.19.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ESnet · iperf3version=0 <3.19.1

Published CVSS scores

8.9MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
10.0NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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.

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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-420Unprotected Alternate Channel
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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