CVE-2022-2127: An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbindd_pam_auth_

This month

MEDIUM 5.9REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2022-2127 is a medium-severity flaw (CVSS 5.9) affecting samba, enterprise linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbindd_pam_auth_crap.c. When performing NTLM authentication, the client replies to cryptographic challenges back to the server. These replies have variable lengths, and Winbind fails to check the lan manager response length. When Winbind is used for NTLM authentication, a maliciously crafted request can trigger an out-of-bounds read in Winbind, possibly

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-125
Published	2023-07-20
Last modified	2026-11-05

Publisher (CNA): Red Hat, Inc. · Vendor: debian · fedoraproject · redhat · samba

Last updated 2026-11-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-07-20 15:15 UTCPublished CVE record published
2026-11-05 09:17 UTCUpdated Record last modified

samba samba UPGRADE

Affected: >= 4.16.0 and < 4.16.10 · >= 4.17.0 and < 4.17.9 · >= 4.18.0 and < 4.18.4

Fixed in: 4.16.10, 4.17.9, 4.18.4

Safe to downgrade to: a release before 4.16.0

1. Check installed version

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

2. UPGRADE to 4.16.10 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade samba

Note

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

3. If no update is available yet, DOWNGRADE to a release before 4.16.0 (Debian / Ubuntu)

apt-cache madison samba sudo apt install samba=<VERSION_BEFORE_4.16.0> sudo apt-mark hold samba

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list samba sudo dnf downgrade samba-<VERSION_BEFORE_4.16.0> sudo dnf versionlock add samba

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat enterprise linux MITIGATE

Affected: 6.0 · 7.0 · 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

fedoraproject fedora MITIGATE

Affected: 37 · 38

Fixed in: no fixed release known

Safe to downgrade to: a release before 37

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.

debian debian linux MITIGATE

Affected: 12.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.0

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-2022-2127?

samba: upgrade to 4.16.10, 4.17.9, 4.18.4; enterprise linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-2127 being exploited?

CVE-2022-2127 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-2022-2127 affect?

CVE-2022-2127 affects samba, enterprise linux, fedora. Severity is medium (CVSS 5.9). An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbindd_pam_auth_crap.c. When performing NTLM authentication, the client replies to cryptographic challenges back to the server. These replies have

How urgent is CVE-2022-2127?

Priority 50/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · Samba vulnerabilities

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References

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