CVE-2021-46671Public exploitNetwork attack vector

Unauthenticated /etc/group disclosure via unterminated TFTP requests

Published Feb 4, 2022 · Updated Aug 4, 2024

Out-of-bounds read in atftp before 0.7.5 allows remote attackers to disclose server-side /etc/group data via a malformed TFTP request. The request and option parsers pass non-null-terminated packet data to argz_next, which performs no bounds checks and reads beyond the received array. Unauthenticated network access to atftpd is sufficient, and the demonstrated consequence is disclosure of group-account metadata rather than memory modification or service interruption.

CVSS severity5.3
Medium
EPSS probability1.27%
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 read in atftp before 0.7.5 allows remote attackers to disclose server-side /etc/group data via a malformed TFTP request. The request and option parsers pass non-null-terminated packet data to argz_next, which performs no bounds checks and reads beyond the received array. Unauthenticated network access to atftpd is sufficient, and the demonstrated consequence is disclosure of group-account metadata rather than memory modification or service interruption.

The record

CVE
CVE-2021-46671
Published
Feb 4, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2022CVE 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

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

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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