[defect]: ntlm_auth failing when using password with backslashes

[antoniotorresm]

What type of defect/bug is this?

Unexpected behaviour (obvious or verified by project member)

How can the issue be reproduced?

1. Configure FreeRADIUS to work with Active Directory using ntlm_auth following: https://deployingradius.com/documents/configuration/active_directory.html
2. Create an user in AD with a password containing backslash:
   New-ADUser -Name Tester -SamAccountName testuser -AccountPassword (ConvertTo-SecureString "vgm%vp|\;PeUQbc#Ojp@" -AsPlainText -Force) -Enabled $true -ChangePasswordAtLogon $false
3. Try to perform an auth:
   radtest testuser "vgm%vp|\;PeUQbc#Ojp@" localhost 0 testing123

If the ntlm_auth command is executed directly, authentication works fine. The issue only happens when using the FreeRADIUS module. Additionally, the FreeRADIUS module works fine when authenticating an user with a password that doesn't contain backslashes.

Log output from the FreeRADIUS daemon

[root@master raddb]# radiusd -X
FreeRADIUS Version 3.2.5
Copyright (C) 1999-2023 The FreeRADIUS server project and contributors
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE
You may redistribute copies of FreeRADIUS under the terms of the
GNU General Public License
For more information about these matters, see the file named COPYRIGHT
Starting - reading configuration files ...
including dictionary file /usr/share/freeradius/dictionary
including dictionary file /usr/share/freeradius/dictionary.dhcp
including dictionary file /usr/share/freeradius/dictionary.vqp
including dictionary file /etc/raddb/dictionary
including configuration file /etc/raddb/radiusd.conf
including configuration file /etc/raddb/proxy.conf
including configuration file /etc/raddb/clients.conf
including files in directory /etc/raddb/mods-enabled/
including configuration file /etc/raddb/mods-enabled/always
including configuration file /etc/raddb/mods-enabled/attr_filter
including configuration file /etc/raddb/mods-enabled/chap
including configuration file /etc/raddb/mods-enabled/date
including configuration file /etc/raddb/mods-enabled/detail
including configuration file /etc/raddb/mods-enabled/detail.log
including configuration file /etc/raddb/mods-enabled/digest
including configuration file /etc/raddb/mods-enabled/dynamic_clients
including configuration file /etc/raddb/mods-enabled/eap
including configuration file /etc/raddb/mods-enabled/echo
including configuration file /etc/raddb/mods-enabled/exec
including configuration file /etc/raddb/mods-enabled/expiration
including configuration file /etc/raddb/mods-enabled/expr
including configuration file /etc/raddb/mods-enabled/files
including configuration file /etc/raddb/mods-enabled/linelog
including configuration file /etc/raddb/mods-enabled/logintime
including configuration file /etc/raddb/mods-enabled/mschap
including configuration file /etc/raddb/mods-enabled/ntlm_auth
including configuration file /etc/raddb/mods-enabled/pap
including configuration file /etc/raddb/mods-enabled/passwd
including configuration file /etc/raddb/mods-enabled/preprocess
including configuration file /etc/raddb/mods-enabled/radutmp
including configuration file /etc/raddb/mods-enabled/realm
including configuration file /etc/raddb/mods-enabled/replicate
including configuration file /etc/raddb/mods-enabled/soh
including configuration file /etc/raddb/mods-enabled/sradutmp
including configuration file /etc/raddb/mods-enabled/totp
including configuration file /etc/raddb/mods-enabled/unix
including configuration file /etc/raddb/mods-enabled/unpack
including configuration file /etc/raddb/mods-enabled/utf8
including files in directory /etc/raddb/policy.d/
including configuration file /etc/raddb/policy.d/accounting
including configuration file /etc/raddb/policy.d/canonicalization
including configuration file /etc/raddb/policy.d/control
including configuration file /etc/raddb/policy.d/cui
including configuration file /etc/raddb/policy.d/debug
including configuration file /etc/raddb/policy.d/dhcp
including configuration file /etc/raddb/policy.d/eap
including configuration file /etc/raddb/policy.d/filter
including configuration file /etc/raddb/policy.d/operator-name
including configuration file /etc/raddb/policy.d/rfc7542
including files in directory /etc/raddb/sites-enabled/
including configuration file /etc/raddb/sites-enabled/default
including configuration file /etc/raddb/sites-enabled/inner-tunnel
main {
 security {
 	user = "radiusd"
 	group = "radiusd"
 	allow_core_dumps = no
 }
	name = "radiusd"
	prefix = "/usr"
	localstatedir = "/var"
	logdir = "/var/log/radius"
	run_dir = "/var/run/radiusd"
}
main {
	name = "radiusd"
	prefix = "/usr"
	localstatedir = "/var"
	sbindir = "/usr/sbin"
	logdir = "/var/log/radius"
	run_dir = "/var/run/radiusd"
	libdir = "/usr/lib64/freeradius"
	radacctdir = "/var/log/radius/radacct"
	hostname_lookups = no
	max_request_time = 30
	proxy_dedup_window = 1
	cleanup_delay = 5
	max_requests = 16384
	max_fds = 512
	postauth_client_lost = no
	pidfile = "/var/run/radiusd/radiusd.pid"
	checkrad = "/usr/sbin/checkrad"
	debug_level = 0
	proxy_requests = yes
 log {
 	stripped_names = no
 	auth = no
 	auth_badpass = no
 	auth_goodpass = no
 	colourise = yes
 	msg_denied = "You are already logged in - access denied"
 }
 resources {
 }
 security {
 	max_attributes = 200
 	reject_delay = 1.000000
 	status_server = yes
 	require_message_authenticator = "auto"
 	limit_proxy_state = "auto"
 }
}
radiusd: #### Loading Realms and Home Servers ####
 proxy server {
 	retry_delay = 5
 	retry_count = 3
 	default_fallback = no
 	dead_time = 120
 	wake_all_if_all_dead = no
 }
 home_server localhost {
 	nonblock = no
 	ipaddr = 127.0.0.1
 	port = 1812
 	type = "auth"
 	secret = <<< secret >>>
 	response_window = 20.000000
 	response_timeouts = 1
 	max_outstanding = 65536
 	zombie_period = 40
 	status_check = "status-server"
 	ping_interval = 30
 	check_interval = 30
 	check_timeout = 4
 	num_answers_to_alive = 3
 	revive_interval = 120
  limit {
  	max_connections = 16
  	max_requests = 0
  	lifetime = 0
  	idle_timeout = 0
  }
  coa {
  	irt = 2
  	mrt = 16
  	mrc = 5
  	mrd = 30
  }
 }
 home_server_pool my_auth_failover {
	type = fail-over
	home_server = localhost
 }
 realm example.com {
	auth_pool = my_auth_failover
 }
 realm LOCAL {
 }
radiusd: #### Loading Clients ####
 client localhost {
 	ipaddr = 127.0.0.1
 	secret = <<< secret >>>
 	nas_type = "other"
 	proto = "*"
  limit {
  	max_connections = 16
  	lifetime = 0
  	idle_timeout = 30
  }
 }
 client localhost_ipv6 {
 	ipv6addr = ::1
 	secret = <<< secret >>>
  limit {
  	max_connections = 16
  	lifetime = 0
  	idle_timeout = 30
  }
 }
Debugger not attached
 # Creating Auth-Type = mschap
 # Creating Auth-Type = digest
 # Creating Auth-Type = eap
 # Creating Auth-Type = NTLM_AUTH
 # Creating Auth-Type = PAP
 # Creating Auth-Type = CHAP
 # Creating Auth-Type = MS-CHAP
 # Creating Autz-Type = New-TLS-Connection
radiusd: #### Instantiating modules ####
 modules {
  # Loaded module rlm_always
  # Loading module "reject" from file /etc/raddb/mods-enabled/always
  always reject {
  	rcode = "reject"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "fail" from file /etc/raddb/mods-enabled/always
  always fail {
  	rcode = "fail"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "ok" from file /etc/raddb/mods-enabled/always
  always ok {
  	rcode = "ok"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "handled" from file /etc/raddb/mods-enabled/always
  always handled {
  	rcode = "handled"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "invalid" from file /etc/raddb/mods-enabled/always
  always invalid {
  	rcode = "invalid"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "userlock" from file /etc/raddb/mods-enabled/always
  always userlock {
  	rcode = "userlock"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "notfound" from file /etc/raddb/mods-enabled/always
  always notfound {
  	rcode = "notfound"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "noop" from file /etc/raddb/mods-enabled/always
  always noop {
  	rcode = "noop"
  	simulcount = 0
  	mpp = no
  }
  # Loading module "updated" from file /etc/raddb/mods-enabled/always
  always updated {
  	rcode = "updated"
  	simulcount = 0
  	mpp = no
  }
  # Loaded module rlm_attr_filter
  # Loading module "attr_filter.post-proxy" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.post-proxy {
  	filename = "/etc/raddb/mods-config/attr_filter/post-proxy"
  	key = "%{Realm}"
  	relaxed = no
  }
  # Loading module "attr_filter.pre-proxy" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.pre-proxy {
  	filename = "/etc/raddb/mods-config/attr_filter/pre-proxy"
  	key = "%{Realm}"
  	relaxed = no
  }
  # Loading module "attr_filter.access_reject" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.access_reject {
  	filename = "/etc/raddb/mods-config/attr_filter/access_reject"
  	key = "%{User-Name}"
  	relaxed = no
  }
  # Loading module "attr_filter.access_challenge" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.access_challenge {
  	filename = "/etc/raddb/mods-config/attr_filter/access_challenge"
  	key = "%{User-Name}"
  	relaxed = no
  }
  # Loading module "attr_filter.accounting_response" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.accounting_response {
  	filename = "/etc/raddb/mods-config/attr_filter/accounting_response"
  	key = "%{User-Name}"
  	relaxed = no
  }
  # Loading module "attr_filter.coa" from file /etc/raddb/mods-enabled/attr_filter
  attr_filter attr_filter.coa {
  	filename = "/etc/raddb/mods-config/attr_filter/coa"
  	key = "%{User-Name}"
  	relaxed = no
  }
  # Loaded module rlm_chap
  # Loading module "chap" from file /etc/raddb/mods-enabled/chap
  # Loaded module rlm_date
  # Loading module "date" from file /etc/raddb/mods-enabled/date
  date {
  	format = "%b %e %Y %H:%M:%S %Z"
  	utc = no
  }
  # Loading module "wispr2date" from file /etc/raddb/mods-enabled/date
  date wispr2date {
  	format = "%Y-%m-%dT%H:%M:%S"
  	utc = no
  }
  # Loaded module rlm_detail
  # Loading module "detail" from file /etc/raddb/mods-enabled/detail
  detail {
  	filename = "/var/log/radius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/detail-%Y%m%d"
  	header = "%t"
  	permissions = 384
  	locking = no
  	dates_as_integer = no
  	escape_filenames = no
  	log_packet_header = no
  }
  # Loading module "auth_log" from file /etc/raddb/mods-enabled/detail.log
  detail auth_log {
  	filename = "/var/log/radius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/auth-detail-%Y%m%d"
  	header = "%t"
  	permissions = 384
  	locking = no
  	dates_as_integer = no
  	escape_filenames = no
  	log_packet_header = no
  }
  # Loading module "reply_log" from file /etc/raddb/mods-enabled/detail.log
  detail reply_log {
  	filename = "/var/log/radius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/reply-detail-%Y%m%d"
  	header = "%t"
  	permissions = 384
  	locking = no
  	dates_as_integer = no
  	escape_filenames = no
  	log_packet_header = no
  }
  # Loading module "pre_proxy_log" from file /etc/raddb/mods-enabled/detail.log
  detail pre_proxy_log {
  	filename = "/var/log/radius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/pre-proxy-detail-%Y%m%d"
  	header = "%t"
  	permissions = 384
  	locking = no
  	dates_as_integer = no
  	escape_filenames = no
  	log_packet_header = no
  }
  # Loading module "post_proxy_log" from file /etc/raddb/mods-enabled/detail.log
  detail post_proxy_log {
  	filename = "/var/log/radius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/post-proxy-detail-%Y%m%d"
  	header = "%t"
  	permissions = 384
  	locking = no
  	dates_as_integer = no
  	escape_filenames = no
  	log_packet_header = no
  }
  # Loaded module rlm_digest
  # Loading module "digest" from file /etc/raddb/mods-enabled/digest
  # Loaded module rlm_dynamic_clients
  # Loading module "dynamic_clients" from file /etc/raddb/mods-enabled/dynamic_clients
  # Loaded module rlm_eap
  # Loading module "eap" from file /etc/raddb/mods-enabled/eap
  eap {
  	default_eap_type = "md5"
  	timer_expire = 60
  	max_eap_type = 52
  	ignore_unknown_eap_types = no
  	cisco_accounting_username_bug = no
  	max_sessions = 16384
  	dedup_key = ""
  }
  # Loaded module rlm_exec
  # Loading module "echo" from file /etc/raddb/mods-enabled/echo
  exec echo {
  	wait = yes
  	program = "/bin/echo %{User-Name}"
  	input_pairs = "request"
  	output_pairs = "reply"
  	shell_escape = yes
  }
  # Loading module "exec" from file /etc/raddb/mods-enabled/exec
  exec {
  	wait = no
  	input_pairs = "request"
  	shell_escape = yes
  	timeout = 10
  }
  # Loaded module rlm_expiration
  # Loading module "expiration" from file /etc/raddb/mods-enabled/expiration
  # Loaded module rlm_expr
  # Loading module "expr" from file /etc/raddb/mods-enabled/expr
  expr {
  	safe_characters = "@abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.-_: /äéöüàâæçèéêëîïôœùûüaÿÄÉÖÜßÀÂÆÇÈÉÊËÎÏÔŒÙÛÜŸ"
  }
  # Loaded module rlm_files
  # Loading module "files" from file /etc/raddb/mods-enabled/files
  files {
  	filename = "/etc/raddb/mods-config/files/authorize"
  	acctusersfile = "/etc/raddb/mods-config/files/accounting"
  	preproxy_usersfile = "/etc/raddb/mods-config/files/pre-proxy"
  }
  # Loaded module rlm_linelog
  # Loading module "linelog" from file /etc/raddb/mods-enabled/linelog
  linelog {
  	filename = "/var/log/radius/linelog"
  	escape_filenames = no
  	syslog_severity = "info"
  	permissions = 384
  	format = "This is a log message for %{User-Name}"
  	reference = "messages.%{%{reply:Packet-Type}:-default}"
  }
  # Loading module "log_accounting" from file /etc/raddb/mods-enabled/linelog
  linelog log_accounting {
  	filename = "/var/log/radius/linelog-accounting"
  	escape_filenames = no
  	syslog_severity = "info"
  	permissions = 384
  	format = ""
  	reference = "Accounting-Request.%{%{Acct-Status-Type}:-unknown}"
  }
  # Loaded module rlm_logintime
  # Loading module "logintime" from file /etc/raddb/mods-enabled/logintime
  logintime {
  	minimum_timeout = 60
  }
  # Loaded module rlm_mschap
  # Loading module "mschap" from file /etc/raddb/mods-enabled/mschap
  mschap {
  	use_mppe = yes
  	require_encryption = no
  	require_strong = no
  	with_ntdomain_hack = yes
   passchange {
   }
  	allow_retry = yes
  	winbind_retry_with_normalised_username = no
  }
  # Loading module "ntlm_auth" from file /etc/raddb/mods-enabled/ntlm_auth
  exec ntlm_auth {
  	wait = yes
  	program = "/usr/bin/ntlm_auth --allow-mschapv2 --request-nt-key --domain=WIN2022.TEST --username=%{mschap:User-Name} --password=%{User-Password}"
  	shell_escape = yes
  }
  # Loaded module rlm_pap
  # Loading module "pap" from file /etc/raddb/mods-enabled/pap
  pap {
  	normalise = yes
  }
  # Loaded module rlm_passwd
  # Loading module "etc_passwd" from file /etc/raddb/mods-enabled/passwd
  passwd etc_passwd {
  	filename = "/etc/passwd"
  	format = "*User-Name:Crypt-Password:"
  	delimiter = ":"
  	ignore_nislike = no
  	ignore_empty = yes
  	allow_multiple_keys = no
  	hash_size = 100
  }
  # Loaded module rlm_preprocess
  # Loading module "preprocess" from file /etc/raddb/mods-enabled/preprocess
  preprocess {
  	huntgroups = "/etc/raddb/mods-config/preprocess/huntgroups"
  	hints = "/etc/raddb/mods-config/preprocess/hints"
  	with_ascend_hack = no
  	ascend_channels_per_line = 23
  	with_ntdomain_hack = no
  	with_specialix_jetstream_hack = no
  	with_cisco_vsa_hack = no
  	with_alvarion_vsa_hack = no
  }
  # Loaded module rlm_radutmp
  # Loading module "radutmp" from file /etc/raddb/mods-enabled/radutmp
  radutmp {
  	filename = "/var/log/radius/radutmp"
  	username = "%{User-Name}"
  	case_sensitive = yes
  	check_with_nas = yes
  	permissions = 384
  	caller_id = yes
  }
  # Loaded module rlm_realm
  # Loading module "IPASS" from file /etc/raddb/mods-enabled/realm
  realm IPASS {
  	format = "prefix"
  	delimiter = "/"
  	ignore_default = no
  	ignore_null = no
  }
  # Loading module "suffix" from file /etc/raddb/mods-enabled/realm
  realm suffix {
  	format = "suffix"
  	delimiter = "@"
  	ignore_default = no
  	ignore_null = no
  }
  # Loading module "bangpath" from file /etc/raddb/mods-enabled/realm
  realm bangpath {
  	format = "prefix"
  	delimiter = "!"
  	ignore_default = no
  	ignore_null = no
  }
  # Loading module "realmpercent" from file /etc/raddb/mods-enabled/realm
  realm realmpercent {
  	format = "suffix"
  	delimiter = "%"
  	ignore_default = no
  	ignore_null = no
  }
  # Loading module "ntdomain" from file /etc/raddb/mods-enabled/realm
  realm ntdomain {
  	format = "prefix"
  	delimiter = "\"
  	ignore_default = no
  	ignore_null = no
  }
  # Loaded module rlm_replicate
  # Loading module "replicate" from file /etc/raddb/mods-enabled/replicate
  # Loaded module rlm_soh
  # Loading module "soh" from file /etc/raddb/mods-enabled/soh
  soh {
  	dhcp = yes
  }
  # Loading module "sradutmp" from file /etc/raddb/mods-enabled/sradutmp
  radutmp sradutmp {
  	filename = "/var/log/radius/sradutmp"
  	username = "%{User-Name}"
  	case_sensitive = yes
  	check_with_nas = yes
  	permissions = 420
  	caller_id = no
  }
  # Loaded module rlm_totp
  # Loading module "totp" from file /etc/raddb/mods-enabled/totp
  totp {
  	time_step = 30
  	otp_length = 6
  	lookback_steps = 1
  	lookback_interval = 30
  	lookforward_steps = 0
  }
  # Loaded module rlm_unix
  # Loading module "unix" from file /etc/raddb/mods-enabled/unix
  unix {
  	radwtmp = "/var/log/radius/radwtmp"
  }
Creating attribute Unix-Group
  # Loaded module rlm_unpack
  # Loading module "unpack" from file /etc/raddb/mods-enabled/unpack
  # Loaded module rlm_utf8
  # Loading module "utf8" from file /etc/raddb/mods-enabled/utf8
  instantiate {
  }
  # Instantiating module "reject" from file /etc/raddb/mods-enabled/always
  # Instantiating module "fail" from file /etc/raddb/mods-enabled/always
  # Instantiating module "ok" from file /etc/raddb/mods-enabled/always
  # Instantiating module "handled" from file /etc/raddb/mods-enabled/always
  # Instantiating module "invalid" from file /etc/raddb/mods-enabled/always
  # Instantiating module "userlock" from file /etc/raddb/mods-enabled/always
  # Instantiating module "notfound" from file /etc/raddb/mods-enabled/always
  # Instantiating module "noop" from file /etc/raddb/mods-enabled/always
  # Instantiating module "updated" from file /etc/raddb/mods-enabled/always
  # Instantiating module "attr_filter.post-proxy" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/post-proxy
  # Instantiating module "attr_filter.pre-proxy" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/pre-proxy
  # Instantiating module "attr_filter.access_reject" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/access_reject
  # Instantiating module "attr_filter.access_challenge" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/access_challenge
  # Instantiating module "attr_filter.accounting_response" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/accounting_response
  # Instantiating module "attr_filter.coa" from file /etc/raddb/mods-enabled/attr_filter
reading pairlist file /etc/raddb/mods-config/attr_filter/coa
  # Instantiating module "detail" from file /etc/raddb/mods-enabled/detail
  # Instantiating module "auth_log" from file /etc/raddb/mods-enabled/detail.log
rlm_detail (auth_log): 'User-Password' suppressed, will not appear in detail output
  # Instantiating module "reply_log" from file /etc/raddb/mods-enabled/detail.log
  # Instantiating module "pre_proxy_log" from file /etc/raddb/mods-enabled/detail.log
  # Instantiating module "post_proxy_log" from file /etc/raddb/mods-enabled/detail.log
  # Instantiating module "eap" from file /etc/raddb/mods-enabled/eap
   # Linked to sub-module rlm_eap_md5
   # Linked to sub-module rlm_eap_gtc
   gtc {
   	challenge = "Password: "
   	auth_type = "PAP"
   }
   # Linked to sub-module rlm_eap_tls
   tls {
   	tls = "tls-common"
   }
   tls-config tls-common {
   	verify_depth = 0
   	ca_path = "/etc/raddb/certs"
   	pem_file_type = yes
   	private_key_file = "/etc/raddb/certs/server.pem"
   	certificate_file = "/etc/raddb/certs/server.pem"
   	ca_file = "/etc/raddb/certs/ca.pem"
   	private_key_password = <<< secret >>>
   	fragment_size = 1024
   	include_length = yes
   	auto_chain = yes
   	check_crl = no
   	check_all_crl = no
   	ca_path_reload_interval = 0
   	cipher_list = "PROFILE=SYSTEM"
   	cipher_server_preference = no
   	reject_unknown_intermediate_ca = no
   	ecdh_curve = ""
   	tls_max_version = "1.2"
   	tls_min_version = "1.2"
    cache {
    	enable = no
    	lifetime = 24
    	max_entries = 255
    }
    verify {
    	skip_if_ocsp_ok = no
    }
    ocsp {
    	enable = no
    	override_cert_url = yes
    	url = "http://127.0.0.1/ocsp/"
    	use_nonce = yes
    	timeout = 0
    	softfail = no
    }
   }
   # Linked to sub-module rlm_eap_ttls
   ttls {
   	tls = "tls-common"
   	default_eap_type = "md5"
   	copy_request_to_tunnel = no
   	use_tunneled_reply = no
   	virtual_server = "inner-tunnel"
   	include_length = yes
   	require_client_cert = no
   }
tls: Using cached TLS configuration from previous invocation
   # Linked to sub-module rlm_eap_peap
   peap {
   	tls = "tls-common"
   	default_eap_type = "mschapv2"
   	copy_request_to_tunnel = no
   	use_tunneled_reply = no
   	proxy_tunneled_request_as_eap = yes
   	virtual_server = "inner-tunnel"
   	soh = no
   	require_client_cert = no
   }
tls: Using cached TLS configuration from previous invocation
   # Linked to sub-module rlm_eap_mschapv2
   mschapv2 {
   	with_ntdomain_hack = no
   	send_error = no
   }
  # Instantiating module "expiration" from file /etc/raddb/mods-enabled/expiration
  # Instantiating module "files" from file /etc/raddb/mods-enabled/files
reading pairlist file /etc/raddb/mods-config/files/authorize
reading pairlist file /etc/raddb/mods-config/files/accounting
reading pairlist file /etc/raddb/mods-config/files/pre-proxy
  # Instantiating module "linelog" from file /etc/raddb/mods-enabled/linelog
  # Instantiating module "log_accounting" from file /etc/raddb/mods-enabled/linelog
  # Instantiating module "logintime" from file /etc/raddb/mods-enabled/logintime
  # Instantiating module "mschap" from file /etc/raddb/mods-enabled/mschap
rlm_mschap (mschap): using internal authentication
  # Instantiating module "pap" from file /etc/raddb/mods-enabled/pap
  # Instantiating module "etc_passwd" from file /etc/raddb/mods-enabled/passwd
rlm_passwd: nfields: 3 keyfield 0(User-Name) listable: no
  # Instantiating module "preprocess" from file /etc/raddb/mods-enabled/preprocess
reading pairlist file /etc/raddb/mods-config/preprocess/huntgroups
reading pairlist file /etc/raddb/mods-config/preprocess/hints
  # Instantiating module "IPASS" from file /etc/raddb/mods-enabled/realm
  # Instantiating module "suffix" from file /etc/raddb/mods-enabled/realm
  # Instantiating module "bangpath" from file /etc/raddb/mods-enabled/realm
  # Instantiating module "realmpercent" from file /etc/raddb/mods-enabled/realm
  # Instantiating module "ntdomain" from file /etc/raddb/mods-enabled/realm
  # Instantiating module "totp" from file /etc/raddb/mods-enabled/totp
 } # modules
radiusd: #### Loading Virtual Servers ####
server { # from file /etc/raddb/radiusd.conf
} # server
server default { # from file /etc/raddb/sites-enabled/default
 # Loading authenticate {...}
Compiling Auth-Type NTLM_AUTH for attr Auth-Type
Compiling Auth-Type PAP for attr Auth-Type
Compiling Auth-Type CHAP for attr Auth-Type
Compiling Auth-Type MS-CHAP for attr Auth-Type
 # Loading authorize {...}
Ignoring "sql" (see raddb/mods-available/README.rst)
Ignoring "ldap" (see raddb/mods-available/README.rst)
Compiling Autz-Type New-TLS-Connection for attr Autz-Type
 # Loading preacct {...}
 # Loading accounting {...}
 # Loading post-proxy {...}
 # Loading post-auth {...}
Compiling Post-Auth-Type REJECT for attr Post-Auth-Type
Compiling Post-Auth-Type Challenge for attr Post-Auth-Type
Compiling Post-Auth-Type Client-Lost for attr Post-Auth-Type
} # server default
server inner-tunnel { # from file /etc/raddb/sites-enabled/inner-tunnel
 # Loading authenticate {...}
Compiling Auth-Type NTLM_AUTH for attr Auth-Type
Compiling Auth-Type PAP for attr Auth-Type
Compiling Auth-Type CHAP for attr Auth-Type
Compiling Auth-Type MS-CHAP for attr Auth-Type
 # Loading authorize {...}
 # Loading session {...}
 # Loading post-proxy {...}
 # Loading post-auth {...}
 # Skipping contents of 'if' as it is always 'false' -- /etc/raddb/sites-enabled/inner-tunnel:372
Compiling Post-Auth-Type REJECT for attr Post-Auth-Type
} # server inner-tunnel
radiusd: #### Opening IP addresses and Ports ####
listen {
  	type = "auth"
  	ipaddr = *
  	port = 0
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
}
listen {
  	type = "acct"
  	ipaddr = *
  	port = 0
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
}
listen {
  	type = "auth"
  	ipv6addr = ::
  	port = 0
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
}
listen {
  	type = "acct"
  	ipv6addr = ::
  	port = 0
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
}
listen {
  	type = "auth"
  	ipaddr = 127.0.0.1
  	port = 18120
}
Listening on auth address * port 1812 bound to server default
Listening on acct address * port 1813 bound to server default
Listening on auth address :: port 1812 bound to server default
Listening on acct address :: port 1813 bound to server default
Listening on auth address 127.0.0.1 port 18120 bound to server inner-tunnel
Listening on proxy address * port 43961
Listening on proxy address :: port 54167
Ready to process requests
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
BlastRADIUS check: Received packet with Message-Authenticator.
Setting "require_message_authenticator = true" for client localhost
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It looks like the client has been updated to protect from the BlastRADIUS attack.
Please set "require_message_authenticator = true" for client localhost
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(0) Received Access-Request Id 139 from 127.0.0.1:52726 to 127.0.0.1:1812 length 94
(0)   Message-Authenticator = 0x229befed4dbea1688b9bc48a6f0e3ed3
(0)   User-Name = "testuser"
(0)   User-Password = "vgm%vp|\\;PeUQbc#Ojp@"
(0)   NAS-IP-Address = 10.0.203.137
(0)   NAS-Port = 0
(0) # Executing section authorize from file /etc/raddb/sites-enabled/default
(0)   authorize {
(0)     policy filter_username {
(0)       if (&User-Name) {
(0)       if (&User-Name)  -> TRUE
(0)       if (&User-Name)  {
(0)         if (&User-Name =~ / /) {
(0)         if (&User-Name =~ / /)  -> FALSE
(0)         if (&User-Name =~ /@[^@]*@/ ) {
(0)         if (&User-Name =~ /@[^@]*@/ )  -> FALSE
(0)         if (&User-Name =~ /\.\./ ) {
(0)         if (&User-Name =~ /\.\./ )  -> FALSE
(0)         if ((&User-Name =~ /@/) && (&User-Name !~ /@(.+)\.(.+)$/))  {
(0)         if ((&User-Name =~ /@/) && (&User-Name !~ /@(.+)\.(.+)$/))   -> FALSE
(0)         if (&User-Name =~ /\.$/)  {
(0)         if (&User-Name =~ /\.$/)   -> FALSE
(0)         if (&User-Name =~ /@\./)  {
(0)         if (&User-Name =~ /@\./)   -> FALSE
(0)       } # if (&User-Name)  = notfound
(0)     } # policy filter_username = notfound
(0)     [preprocess] = ok
(0)     [chap] = noop
(0)     [mschap] = noop
(0)     [digest] = noop
(0) suffix: Checking for suffix after "@"
(0) suffix: No '@' in User-Name = "testuser", looking up realm NULL
(0) suffix: No such realm "NULL"
(0)     [suffix] = noop
(0) eap: No EAP-Message, not doing EAP
(0)     [eap] = noop
(0) files: users: Matched entry DEFAULT at line 5
(0)     [files] = ok
(0)     [expiration] = noop
(0)     [logintime] = noop
Not doing PAP as Auth-Type is already set.
(0)     [pap] = noop
(0)   } # authorize = ok
(0) Found Auth-Type = NTLM_AUTH
(0) # Executing group from file /etc/raddb/sites-enabled/default
(0)   Auth-Type NTLM_AUTH {
(0) ntlm_auth: Executing: /usr/bin/ntlm_auth --allow-mschapv2 --request-nt-key --domain=WIN2022.TEST --username=%{mschap:User-Name} --password=%{User-Password}:
(0) ntlm_auth: EXPAND --username=%{mschap:User-Name}
(0) ntlm_auth:    --> --username=testuser
(0) ntlm_auth: EXPAND --password=%{User-Password}
(0) ntlm_auth:    --> --password=vgm%vp|\\;PeUQbc#Ojp@
(0) ntlm_auth: ERROR: Program returned code (1) and output 'NT_STATUS_WRONG_PASSWORD: When trying to update a password, this return status indicates that the value provided as the current password is not correct. (0xc000006a)'
(0)     [ntlm_auth] = reject
(0)   } # Auth-Type NTLM_AUTH = reject
(0) Failed to authenticate the user
(0) Using Post-Auth-Type Reject
(0) # Executing group from file /etc/raddb/sites-enabled/default
(0)   Post-Auth-Type REJECT {
(0) attr_filter.access_reject: EXPAND %{User-Name}
(0) attr_filter.access_reject:    --> testuser
(0) attr_filter.access_reject: Matched entry DEFAULT at line 11
(0)     [attr_filter.access_reject] = updated
(0)     [eap] = noop
(0)     policy remove_reply_message_if_eap {
(0)       if (&reply:EAP-Message && &reply:Reply-Message) {
(0)       if (&reply:EAP-Message && &reply:Reply-Message)  -> FALSE
(0)       else {
(0)         [noop] = noop
(0)       } # else = noop
(0)     } # policy remove_reply_message_if_eap = noop
(0)   } # Post-Auth-Type REJECT = updated
(0) Delaying response for 1.000000 seconds
Waking up in 0.2 seconds.
Waking up in 0.7 seconds.
(0) Sending delayed response
(0) Sent Access-Reject Id 139 from 127.0.0.1:1812 to 127.0.0.1:52726 length 38
Waking up in 3.9 seconds.
(0) Cleaning up request packet ID 139 with timestamp +15 due to cleanup_delay was reached
Ready to process requests

Relevant log output from client utilities

radtest with a password containing backslash:

# radtest testuser "vgm%vp|\;PeUQbc#Ojp@" localhost 0 testing123
Sent Access-Request Id 139 from 0.0.0.0:52726 to 127.0.0.1:1812 length 94
	User-Name = "testuser"
	User-Password = "vgm%vp|\\;PeUQbc#Ojp@"
	NAS-IP-Address = 10.0.203.137
	NAS-Port = 0
	Message-Authenticator = 0x00
	Cleartext-Password = "vgm%vp|\\;PeUQbc#Ojp@"
Received Access-Reject Id 139 from 127.0.0.1:1812 to 127.0.0.1:52726 length 38
	Message-Authenticator = 0xf0a1a7a94be54b2c0b3b116886d2e6e7
(0) -: Expected Access-Accept got Access-Reject

radtest with a password without backslashes:

# radtest testuser2 "password" localhost 0 testing123
Sent Access-Request Id 127 from 0.0.0.0:53555 to 127.0.0.1:1812 length 79
	User-Name = "testuser2"
	User-Password = "password"
	NAS-IP-Address = 10.0.203.137
	NAS-Port = 0
	Message-Authenticator = 0x00
	Cleartext-Password = "password"
Received Access-Accept Id 127 from 127.0.0.1:1812 to 127.0.0.1:53555 length 38
	Message-Authenticator = 0xf1dc149534a69801901cc7a7c40dc0e3

ntlm_auth working with the password with backslashes:

# ntlm_auth --request-nt-key --domain=WIN2022.TEST --username=testuser --password="vgm%vp|\;PeUQbc#Ojp@"
:  (0x0)

Backtrace from LLDB or GDB

[alandekok]

This may be a difficult issue to solve in v3. For security, it escapes most "bad" characters when they're printed.

In this case, FreeRADIUS doesn't know whether or not the shell will un-escape the string. So any fix needs to not only be correct, but also not break anything else.