SMB NULL Session Authentication

high Nessus Plugin ID 26920


It is possible to log into the remote Windows host with a NULL session.


The remote host is running and SMB protocol. It is possible to log into the browser or spoolss pipes using a NULL session (i.e., with no login or password).

Depending on the configuration, it may be possible for an unauthenticated, remote attacker to leverage this issue to get information about the remote host.


Please contact the product vendor for recommended solutions.

See Also

Plugin Details

Severity: High

ID: 26920

File Name: smb_null_session.nasl

Version: 1.41

Type: remote

Agent: windows

Family: Windows

Published: 10/4/2007

Updated: 6/24/2022

Supported Sensors: Nessus Agent

Risk Information


Risk Factor: Medium

Score: 5.8


Risk Factor: High

Base Score: 7.5

Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-1999-0519


Risk Factor: High

Base Score: 7.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Vulnerability Information

CPE: cpe:/o:microsoft:windows

Required KB Items: SMB/null_session_suspected

Vulnerability Publication Date: 7/14/1999

Reference Information

CVE: CVE-1999-0519, CVE-1999-0520, CVE-2002-1117

BID: 494