CVE-2021-46671: options.c in atftp before 0.7.5 reads past the end of an array, and consequently discloses server-side /etc/gr

Q: How do I fix CVE-2021-46671?

atftp: upgrade to 0.7.5; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2021-46671 being exploited?

CVE-2021-46671 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-46671 affect?

CVE-2021-46671 affects atftp, debian linux. Severity is medium (CVSS 5.3). options.c in atftp before 0.7.5 reads past the end of an array, and consequently discloses server-side /etc/group data to a remote client.

Q: How urgent is CVE-2021-46671?

Priority 51/100. Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

This week

MEDIUM 5.3REMOTEWATCHLISTUPGRADEMITIGATE

CVE-2021-46671 is a medium-severity flaw (CVSS 5.3) affecting atftp, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

options.c in atftp before 0.7.5 reads past the end of an array, and consequently discloses server-side /etc/group data to a remote client.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-125
Published	2022-02-04
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: atftp project · debian

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-02-04 21:15 UTCPublished CVE record published
2026-06-17 04:15 UTCUpdated Record last modified

atftp project atftp UPGRADE

Affected: < 0.7.5

Fixed in: 0.7.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy atftp || rpm -q atftp || atftp --version

2. UPGRADE to 0.7.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade atftp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade atftp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 9.0 · 10.0 · 11.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-46671?

atftp: upgrade to 0.7.5; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-46671 being exploited?

CVE-2021-46671 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-46671 affect?

CVE-2021-46671 affects atftp, debian linux. Severity is medium (CVSS 5.3). options.c in atftp before 0.7.5 reads past the end of an array, and consequently discloses server-side /etc/group data to a remote client.

How urgent is CVE-2021-46671?

Priority 51/100. Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2021-41054 HIGH 7.5 UPGRADE MITIGATE tftpd_file.c in atftp through 0.7.4 has a buffer overflow because buffer-size handling does not properly consi
CVE-2020-6097 HIGH 7.5 MITIGATE MITIGATE An exploitable denial of service vulnerability exists in the atftpd daemon functionality of atftp 0.7.git20120

References

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