Nmap samba-vuln-cve-2012-1182 NSE Script


This page contains detailed information about how to use the samba-vuln-cve-2012-1182 NSE script. For list of all NSE scripts, visit the Nmap NSE Library.

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Script Overview

Script source code: https://github.com/nmap/nmap/tree/master/scripts/samba-vuln-cve-2012-1182.nse
Script categories: vuln, intrusive
Target service / protocol: netbios-ssn
Target network port(s): 139
List of CVEs: CVE-2012-1182

Script Description

The samba-vuln-cve-2012-1182.nse script checks if target machines are vulnerable to the Samba heap overflow vulnerability CVE-2012-1182.

Samba versions 3.6.3 and all versions previous to this are affected by a vulnerability that allows remote code execution as the "root" user from an anonymous connection.

CVE-2012-1182 marks multiple heap overflow vulnerabilities located in PIDL based autogenerated code. This check script is based on PoC by ZDI marked as ZDI-CAN-1503. Vulnerability lies in ndr_pull_lsa_SidArray function where an attacker is under control of num_sids and can cause insufficient memory to be allocated, leading to heap buffer overflow and possibility of remote code execution.

Script builds a malicious packet and makes a SAMR GetAliasMembership call which triggers the vulnerability. On the vulnerable system, connection is dropped and result is "Failed to receive bytes after 5 attempts". On patched system, samba throws an error and result is "MSRPC call returned a fault (packet type)".

References:

Samba-vuln-cve-2012-1182 NSE Script Arguments

This is a full list of arguments supported by the samba-vuln-cve-2012-1182.nse script:

smbdomain

The domain to log in with. If you aren't in a domain environment, then anything will (should?) be accepted by the server.

smbhash

A password hash to use when logging in. This is given as a single hex string (32 characters) or a pair of hex strings (both 32 characters, optionally separated by a single character). These hashes are the LanMan or NTLM hash of the user's password, and are stored on disk or in memory. They can be retrieved from memory using the fgdump or pwdump tools.

smbnoguest

Use to disable usage of the 'guest' account.

smbpassword

The password to connect with. Be cautious with this, since some servers will lock accounts if the incorrect password is given. Although it's rare that the Administrator account can be locked out, in the off chance that it can, you could get yourself in trouble. To use a blank password, leave this parameter off altogether.

smbtype

The type of SMB authentication to use. These are the possible options:

  • v1: Sends LMv1 and NTLMv1.
  • LMv1: Sends LMv1 only.
  • NTLMv1: Sends NTLMv1 only (default).
  • v2: Sends LMv2 and NTLMv2.
  • LMv2: Sends LMv2 only.
  • NTLMv2: Doesn't exist; the protocol doesn't support NTLMv2 alone. The default, NTLMv1, is a pretty decent compromise between security and compatibility. If you are paranoid, you might want to use v2 or lmv2 for this. (Actually, if you're paranoid, you should be avoiding this protocol altogether!). If you're using an extremely old system, you might need to set this to v1 or lm, which are less secure but more compatible. For information, see smbauth.lua.

smbusername

The SMB username to log in with. The forms "DOMAIN\username" and "username@DOMAIN" are not understood. To set a domain, use the smbdomain argument.

randomseed

Set to a value to change the filenames/service names that are randomly generated.

smbbasic

Forces the authentication to use basic security, as opposed to "extended security". Against most modern systems, extended security should work, but there may be cases where you want to force basic. There's a chance that you'll get better results for enumerating users if you turn on basic authentication.

smbport

Override the default port choice. If smbport is open, it's used. It's assumed to be the same protocol as port 445, not port 139. Since it probably isn't possible to change Windows' ports normally, this is mostly useful if you're bouncing through a relay or something.

smbsign

Controls whether or not server signatures are checked in SMB packets. By default, on Windows, server signatures aren't enabled or required. By default, this library will always sign packets if it knows how, and will check signatures if the server says to. Possible values are:

  • force: Always check server signatures, even if server says it doesn't support them (will Probably fail, but is technically more secure).
  • negotiate: [default] Use signatures if server supports them.
  • ignore: Never check server signatures. Not recommended.
  • disable: Don't send signatures, at all, and don't check the server's. not recommended. More information on signatures can be found in smbauth.lua.

vulns.short

If set, vulnerabilities will be output in short format, a single line consisting of the host's target name or IP, the state, and either the CVE ID or the title of the vulnerability. Does not affect XML output.

vulns.showall

If set, the library will show and report all the registered vulnerabilities which includes the NOT VULNERABLE ones. By default the library will only report the VULNERABLE entries: VULNERABLE, LIKELY VULNERABLE, VULNERABLE (DoS) and VULNERABLE (Exploitable). This argument affects the following functions: vulns.Report.make_output(): the default output function for portule/hostrule scripts. vulns.make_output(): the default output function for postrule scripts. vulns.format_vuln() and vulns.format_vuln_table() functions.

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To use these script arguments, add them to the Nmap command line using the --script-args arg1=value,[arg2=value,..] syntax. For example:

nmap --script=samba-vuln-cve-2012-1182 --script-args smbdomain=value,smbhash=value <target>

Samba-vuln-cve-2012-1182 NSE Script Example Usage

Here's an example of how to use the samba-vuln-cve-2012-1182.nse script:

nmap --script=samba-vuln-cve-2012-1182  -p 139 <target>

Samba-vuln-cve-2012-1182 NSE Script Example Output

Here's a sample output from the samba-vuln-cve-2012-1182.nse script:

PORT    STATE SERVICE
139/tcp open  netbios-ssn

Host script results:
| samba-vuln-cve-2012-1182:
|   VULNERABLE:
|   SAMBA remote heap overflow
|     State: VULNERABLE
|     IDs:  CVE:CVE-2012-1182
|     Risk factor: HIGH  CVSSv2: 10.0 (HIGH) (AV:N/AC:L/Au:N/C:C/I:C/A:C)
|     Description:
|       Samba versions 3.6.3 and all versions previous to this are affected by
|       a vulnerability that allows remote code execution as the "root" user
|       from an anonymous connection.
|
|     Disclosure date: 2012-03-15
|     References:
|       http://www.samba.org/samba/security/CVE-2012-1182
|_      http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-1182

Samba-vuln-cve-2012-1182 NSE Script Example XML Output

There is no sample XML output for this module. However, by providing the -oX <file> option, Nmap will produce a XML output and save it in the file.xml file.

Author

  • Aleksandar Nikolic

References

See Also

Visit Nmap NSE Library for more scripts.

The samba-vuln-cve-2012-1182.nse script may fail with the following error messages. Check for the possible causes by using the code snippets highlighted below found in the script source code. This can often times help in identifying the root cause of the problem.

Failed to receive bytes after 5 attempts

Here is a relevant code snippet related to the "Failed to receive bytes after 5 attempts" error message:

19:	insufficient memory to be allocated, leading to heap buffer overflow
20:	and possibility of remote code execution.
21:	
22:	Script builds a malicious packet and makes a SAMR GetAliasMembership
23:	call which triggers the vulnerability. On the vulnerable system,
24:	connection is dropped and result is "Failed to receive bytes after 5 attempts".
25:	On patched system, samba throws an error and result is  "MSRPC call
26:	returned a fault (packet type)".
27:	
28:	References:
29:	* https://bugzilla.samba.org/show_bug.cgi?id=8815

Version

This page has been created based on Nmap version 7.92.

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