CVE-2021-41054Public exploitNetwork attack vector

Service crash via miscalculated TFTP response buffer

Published Sep 13, 2021 · Updated Aug 4, 2024

A buffer overflow in atftp through 0.7.4 allows remote attackers to crash the atftpd server with a crafted TFTP read request. In tftpd_file.c, response-buffer sizing fails to account for file data, the OACK header, and multiple negotiated option strings written together. No authentication or user interaction is required; successful exploitation terminates the daemon and interrupts TFTP service.

CVSS severity7.5
High
EPSS probability2.32%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A buffer overflow in atftp through 0.7.4 allows remote attackers to crash the atftpd server with a crafted TFTP read request. In tftpd_file.c, response-buffer sizing fails to account for file data, the OACK header, and multiple negotiated option strings written together. No authentication or user interaction is required; successful exploitation terminates the daemon and interrupts TFTP service.

The record

CVE
CVE-2021-41054
Published
Sep 13, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

Public exploit references

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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