dbcve.org
FedoraOperating system · Fedoraproject

CVE-2022-3437

MEDIUM · 6.5 CVSS v3.1 Published 2023-01-12
Fix available
A fix is available. Upgrade to 4.15.11 / 4.16.6 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A heap-based buffer overflow vulnerability was found in Samba within the GSSAPI unwrap_des() and unwrap_des3() routines of Heimdal. The DES and Triple-DES decryption routines in the Heimdal GSSAPI library allow a length-limited write buffer overflow on malloc() allocated memory when presented with a maliciously small packet. This flaw allows a remote user to send specially crafted malicious data to the application, possibly resulting in a denial of service (DoS) attack.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Heap-based buffer overflow in Samba's Heimdal GSSAPI library in the unwrap_des() and unwrap_des3() DES/Triple-DES decryption routines. When processing a maliciously small packet, the length validation allows a write beyond the allocated malloc() buffer boundaries, leading to potential denial of service.

MitigationUpdate Samba to the version containing the fix. If immediate patching is not possible, consider disabling DES/3DES in the GSSAPI configuration or restricting network access to affected services until the patch can be applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FedoraOperating system
Affected:= 36= 37
SambaApplication
Affected:>= 4.0.0, < 4.15.11>= 4.16.0, < 4.16.6>= 4.17.0, < 4.17.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if Samba is installed
    Run 'smbd --version' or 'samba --version' to get the Samba version. On Fedora/RHEL, also run 'rpm -q samba'
    Affected if Samba is installed and the version falls within 4.0.0 to 4.15.10, 4.16.0 to 4.16.5, or 4.17.0 to 4.17.1
  2. Confirm the vulnerable code path exists
    Verify the Heimdal GSSAPI library is present. Check for existence of the file libgssapi or equivalent GSSAPI library shipped with Samba in the Samba library directory
    Affected if The Heimdal GSSAPI library with DES/3DES support is present in the Samba installation
  3. Check if DES/3DES is enabled in GSSAPI configuration
    Inspect /etc/krb5.conf and /etc/samba/smb.conf for any configuration that explicitly enables DES or 3DES encryption types (look for 'des-cbc-crc', 'des-cbc-md5', 'des3-cbc-sha1' or similar in encryption types settings)
    Affected if DES or 3DES encryption types are explicitly listed as enabled in the Kerberos or Samba configuration files
  4. Verify network exposure of Samba services
    Check if smbd, winbind, or other Samba services are listening on network interfaces by running 'netstat -tulpn | grep -E "smbd|winbind"' or 'ss -tulpn | grep -E "smbd|winbind"'
    Affected if Samba services are bound to network interfaces and accessible from the network

You are affected if Samba is installed with a version in the vulnerable ranges AND DES/3DES support is enabled in your GSSAPI/Kerberos configuration, exposing the vulnerable decryption routines.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.15.11 / 4.16.6 / 4.17.2 or later
Fixed in 4.15.114.16.64.17.2
Interim mitigation

Update Samba to the version containing the fix. If immediate patching is not possible, consider disabling DES/3DES in the GSSAPI configuration or restricting network access to affected services until the patch can be applied.

Recommended fix High confidence

Samba 4.17.11 (or latest 4.17.x) - alternatively 4.16.11 (4.16.x) or 4.15.13 (4.15.x) depending on branch

  1. 1. Check current Samba version: smbd --version or rpm -q samba
  2. 2. For Samba 4.0.0 to 4.15.x: Upgrade to Samba 4.15.11 or later (recommended: 4.15.13 or latest 4.15.x)
  3. 3. For Samba 4.16.0 to 4.16.x: Upgrade to Samba 4.16.6 or later (recommended: 4.16.11 or latest 4.16.x)
  4. 4. For Samba 4.17.0 to 4.17.2: Upgrade to Samba 4.17.2 or later (recommended: 4.17.11 or latest 4.17.x)
  5. 5. On Fedora systems: Run 'dnf update samba' to apply available security patches
  6. 6. Restart Samba services after upgrade: 'systemctl restart smb nmb'
  7. 7. Verify the new version is running: smbd --version
Caveat Samba upgrades may require configuration review; ensure backups of smb.conf and existing configurations before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Fedora Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-3437 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data