CVE-2016-2124

Description

A flaw was found in the way samba implemented SMB1 authentication. An attacker could use this flaw to retrieve the plaintext password sent over the wire even if Kerberos authentication was required.

Mitigation

Ensure the following [global] smb.conf parameters are set to their default values as shown below:

  client lanman auth = no
client NTLMv2 auth = yes
client plaintext auth = no
client min protocol = SMB2_02

Or use the '-k' command line option only without the -U option, which will make use of an existing krb5 ccache.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.85.9N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityHighHighN/A
Privileges RequiredLowNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityHighHighN/A
Integrity ImpactHighNoneN/A
Availability ImpactNoneNoneN/A

Vector

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

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

Understanding the Weakness (CWE)

Integrity,Confidentiality,Availability,Access Control

Technical Impact: Read Application Data; Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands

This weakness can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with sensitive information or even execute arbitrary code.

Acknowledgements

Red Hat would like to thank Stefan Metzmacher (SerNet) for reporting this issue. Upstream acknowledges the Samba project as the original reporter.

Frequently Asked Questions

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