Coverage › CVE-2021-22893
CVE-2021-22893 Mapped Sigma
Ivanti Pulse Connect Secure Use-After-Free Vulnerability
- Vendor / product
- Ivanti — Pulse Connect Secure
- Description (CISA)
- Ivanti Pulse Connect Secure contains a use-after-free vulnerability that allow a remote, unauthenticated attacker to execute code via license services.
- Added to KEV
- 2021-11-03
- Due date
- 2022-05-03
- Required action
- Apply updates per vendor instructions.
- Known ransomware use
- Known
- CWE
- CWE-287
- CISA notes
- Reference CISA's ED 21-03 (https://www.cisa.gov/news-events/directives/ed-21-03-mitigate-pulse-connect-secure-product-vulnerabilities) for further guidance and requirements. Note: The due date for addressing this vulnerability aligns with the requirements outlined in ED 21-03. https://nvd.nist.gov/vuln/detail/CVE-2021-22893
- Elsewhere
- cve.org · NVD · CISA KEV · JSON
ATT&CK techniques · CTID Mappings Explorer, ATT&CK 16.1, KEV snapshot 2025-07-28
3 mapping objects across 3 techniques. exploitation technique states how the vulnerability is exploited; primary and secondary impact state what exploitation achieves. They are different claims and are labelled as such.
| Technique | Mapping type | CTID comment | Status in v19.2 |
|---|---|---|---|
| T1190 Exploit Public-Facing Application | exploitation technique | This vulnerability is exploited through an authentication bypass weakness in the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure. Remote attackers leverage this vulnerability to perform remote arbitrary code execution on the Pulse Connect Secure gateway by bypassing authentication controls. The threat actor group UNC2630 has utilized this flaw to harvest login credentials, allowing them to move laterally within affected environments. ref 1 |
live |
| T1003 OS Credential Dumping | secondary impact | This vulnerability is exploited through an authentication bypass weakness in the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure. Remote attackers leverage this vulnerability to perform remote arbitrary code execution on the Pulse Connect Secure gateway by bypassing authentication controls. The threat actor group UNC2630 has utilized this flaw to harvest login credentials, allowing them to move laterally within affected environments. ref 1 |
live |
| T1059 Command and Scripting Interpreter | primary impact | This vulnerability is exploited through an authentication bypass weakness in the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure. Remote attackers leverage this vulnerability to perform remote arbitrary code execution on the Pulse Connect Secure gateway by bypassing authentication controls. The threat actor group UNC2630 has utilized this flaw to harvest login credentials, allowing them to move laterally within affected environments. ref 1 |
live |
Detection chain · ATT&CK Enterprise v19.2 detection strategies, analytics, log sources
T1003 OS Credential Dumping secondary impact
- DET0234 Credential Dumping via Sensitive Memory and Registry Access Correlation
AN0648 WindowsProcesses accessing LSASS memory or SAM registry hives outside of trusted security tools, often followed by file creation or lateral movement. Detects unauthorized access to sensitive OS subsystems for credential extraction.Tunable:
AccessMaskTimeWindowParentProcessFilterAN0649 LinuxProcesses opening /proc//mem or /proc//maps targeting credential-storing services like sshd or login. Behavior often includes high privilege escalation and memory inspection tools such as gcore or gdb.Tunable:TargetProcessNameToolProcessNameAN0650 macOSUnsigned processes accessing system memory or launching known credential scraping tools (e.g., osascript, dylib injections) to access the Keychain or sensitive memory regions.Tunable:KeychainAccessPathSignedBinaryStatus
Sigma rules tagged attack.t1003 (37)
Author: Nasreddine Bencherchali (Nextron Systems)
· 2022-08-23 (modified 2023-08-17) · logsource: product=windows category=registry_set · 0442defa-b4a2-41c9-ae2c-ea7042fc4701
Detects when an attacker tries to add a new network provider in order to dump clear text credentials, similar to how the NPPSpy tool does it
Author: Tim Rauch, Elastic (idea)
· 2022-09-28 · logsource: product=windows category=ps_script · 189e3b02-82b2-4b90-9662-411eb64486d4
Detects Invoke-Mimikatz PowerShell script and alike. Mimikatz is a credential dumper capable of obtaining plaintext Windows account logins and passwords.
Author: Thomas Patzke
· 2017-06-14 (modified 2025-01-30) · logsource: product=windows service=security · 1de68c67-af5c-4097-9c85-fe5578e09e67
Detects wceaux.dll access while WCE pass-the-hash remote command execution on source host
Author: Florian Roth (Nextron Systems)
· 2022-03-04 (modified 2024-11-23) · logsource: product=windows category=process_creation · 24e3e58a-646b-4b50-adef-02ef935b9fc8
Detects the execution of different Windows based hacktools via their import hash (imphash) even if the files have been renamed
Author: Florian Roth (Nextron Systems), David ANDRE (additional keywords)
· 2021-12-20 (modified 2025-10-19) · logsource: product=windows category=process_creation · 2617e7ed-adb7-40ba-b0f3-8f9945fe6c09
Detects a suspicious process creation as SYSTEM user (suspicious program or command line parameter)
Author: Tim Rauch, Janantha Marasinghe, Elastic (original idea)
· 2022-11-08 (modified 2023-01-22) · logsource: product=windows category=process_creation · 2d3cdeec-c0db-45b4-aa86-082f7eb75701
Detects the Internet Information Services (IIS) command-line tool, AppCmd, being used to list passwords
Author: Christian Burkard (Nextron Systems), Florian Roth (Nextron Systems)
· 2023-04-27 · logsource: product=windows category=ps_script · 3245cd30-e015-40ff-a31d-5cadd5f377ec
Detects the execution of the hacktool Rubeus using specific command line flags
Author: Milad Cheraghi
· 2026-04-28 · logsource: product=linux category=process_creation · 33b3cfb1-574e-44b9-b527-fbf9303b9d7b
Detects attempts of an attacker to enable core dumps for set-user-ID (SUID) processes by modifying the system file /proc/sys/fs/suid_dumpable, typically by setting its value to 1 or 2.
Enabling this feature allows memory dumps (core dumps) of SUID processes, which usually run with elevated privileges.
These dumps may contain sensitive information such as passwords, cryptographic keys or other secrets.
CVE-2025-5054: Information leak via core dumps from SUID binaries using apport.
CVE-2025-4598: Information disclosure in systemd-coredump due to insecure handling of SUID process memory dumps.
Author: Swachchhanda Shrawan Poudel
· 2024-02-12 (modified 2024-03-13) · logsource: product=windows category=process_creation · 34275eb8-fa19-436b-b959-3d9ecd53fa1f
Detects the enumeration of a specific DLL or EXE being used by a binary via "tasklist.exe".
This is often used by attackers in order to find the specific process identifier (PID) that is using the DLL in question.
In order to dump the process memory or perform other nefarious actions.
Author: Florian Roth (Nextron Systems)
· 2022-04-27 (modified 2024-01-15) · logsource: product=windows category=process_creation · 37c1333a-a0db-48be-b64b-7393b2386e3b
Detects the execution of different Windows based hacktools via PE metadata (company, product, etc.) even if the files have been renamed
Author: Security Onion Solutions
· 2024-03-08 · logsource: product=opencanary category=application · 3ec9a16d-0b4f-4967-9542-ebf38ceac7dd
Detects instances where an MSSQL service on an OpenCanary node has had a login attempt using SQLAuth.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2022-10-11 (modified 2026-07-28) · logsource: product=windows category=file_access · 407aecb1-e762-4acf-8c7b-d087bcff3bb6
Detects suspicious processes based on name and location that access the windows credential manager and vault.
Which can be a sign of credential stealing. Example case would be usage of mimikatz "dpapi::cred" function
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
· 2025-11-27 (modified 2026-01-09) · logsource: product=windows category=image_load · 416bc4a2-7217-4519-8dc7-c3271817f1d5
Detects loading of dbgcore.dll or dbghelp.dll from uncommon locations such as user directories.
These DLLs contain the MiniDumpWriteDump function, which can be abused for credential dumping purposes or in some cases for evading EDR/AV detection by suspending processes.
Author: Pawel Mazur
· 2021-05-24 (modified 2022-12-18) · logsource: product=linux service=auditd · 49aae26c-450e-448b-911d-b3c13d178dfc
Detect attempt to enable auditing of TTY input
Author: Security Onion Solutions
· 2024-03-08 · logsource: product=opencanary category=application · 547dfc53-ebf6-4afe-8d2e-793d9574975d
Detects instances where a REDIS service on an OpenCanary node has had an action command attempted.
All 37 rules on the technique page →
T1059 Command and Scripting Interpreter primary impact
- DET0516 Behavioral Detection of Command and Scripting Interpreter Abuse
AN1428 WindowsDetects the execution of scripting or command interpreters (e.g., powershell.exe, cmd.exe, wscript.exe) outside expected administrative time windows or from abnormal user contexts, often followed by encoded/obfuscated arguments or secondary execution events.Tunable:
CommandLinePatternParentProcessNameTimeWindowAN1429 LinuxDetects use of shell interpreters (e.g., bash, sh, python, perl) initiated by users or processes not normally executing them, especially when chaining suspicious utilities like netcat, curl, or ssh.Tunable:InterpreterNameUserContextExecutionChainLengthAN1430 macOSDetects launch of command-line interpreters via Terminal, Automator, or hiddenosascript, especially when parent process lineage deviates from user-initiated applications.macos:unifiedloglog stream --info --predicate 'eventMessage CONTAINS "exec"'→ DC0032 Process CreationTunable:LaunchAgentNameScriptNameTerminalAppUsageAN1431 ESXiDetects use of 'esxcli system' or direct interpreter commands (e.g., busybox shell) invoked from SSH or host terminal unexpectedly.Tunable:ShellEnabledFlagSSHContextAN1432 Network DevicesIdentifies CLI interpreter access (e.g., Cisco IOS, Juniper JUNOS) viaenablemode or scripting-capable sessions used by uncommon accounts or from unknown IPs.Tunable:UserRoleDeviceType
Sigma rules tagged attack.t1059 (95)
Author: Sohan G (D4rkCiph3r)
· 2023-04-05 · logsource: product=macos category=process_creation · 0250638a-2b28-4541-86fc-ea4c558fa0c6
Detects suspicious child processes spawned from browsers. This could be a result of a potential web browser exploitation.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2023-04-17 · logsource: product=windows category=process_creation · 05ebafc8-7aa2-4bcd-a269-2aec93f9e842
Detects usage of winget to add new additional download sources
Author: Victor Sergeev, oscd.community
· 2020-10-09 (modified 2024-04-23) · logsource: product=windows category=process_creation · 06b401f4-107c-4ff9-947f-9ec1e7649f1e
Detects execution of "ftp.exe" script with the "-s" or "/s" flag and any child processes ran by "ftp.exe".
Author: Nasreddine Bencherchali (Nextron Systems), E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.community
· 2022-06-14 (modified 2023-01-04) · logsource: product=windows category=process_creation · 0955e4e1-c281-4fb9-9ee1-5ee7b4b754d2
Detects execition of commands and binaries from the context of The program compatibility assistant (Pcalua.exe). This can be used as a LOLBIN in order to bypass application whitelisting.
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
· 2025-11-25 · logsource: product=linux category=process_creation · 11bb9b26-4179-4a06-afcb-1ec31fce1627
Detects potential Shai-Hulud malware indicators based on specific command line arguments associated with its execution.
Author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
· 2022-02-08 (modified 2026-02-17) · logsource: product=windows category=process_creation · 1228c958-e64e-4e71-92ad-7d429f4138ba
Detects suspicious script execution from suspicious directories or folders accessible by environment variables that may indicate malware activity.
Script interpreters (cscript, wscript, mshta, powershell) executing from folders like Temp, Public, or user profile directories may suggest attempts to evade detection or execute malicious scripts.
Author: Josh Nickels, Marius Rothenbücher
· 2024-09-06 · logsource: product=windows category=dns_query · 12310575-e8b1-475c-a976-57ed540b349c
Detects unusual domain resolutions originating from CScript/WScript that can identify malicious javascript files executing in an environment, often as a result from a phishing or watering hole attack.
Author: Florian Roth (Nextron Systems)
· 2021-11-20 (modified 2023-03-29) · logsource: product=windows category=file_event · 1277f594-a7d1-4f28-a2d3-73af5cbeab43
Detects Windows shells and scripting applications that write files to suspicious folders
Author: frack113, Tim Shelton (update fp)
· 2022-12-05 (modified 2025-03-06) · logsource: product=windows category=process_creation · 178e615d-e666-498b-9630-9ed363038101
Detects when a shell program such as the Windows command prompt or PowerShell is launched with system privileges from a uncommon parent location.
Author: Micah Babinski
· 2023-10-15 · logsource: product=windows category=file_event · 1a433e1d-03d2-47a6-8063-ece992cf4e73
Detects the usage of curl.exe, KeyScramblerLogon, or other non-standard/suspicious processes used to create Autoit3.exe.
This activity has been associated with DarkGate malware, which uses Autoit3.exe to execute shellcode that performs
process injection and connects to the DarkGate command-and-control server. Curl, KeyScramblerLogon, and these other
processes consitute non-standard and suspicious ways to retrieve the Autoit3 executable.
Author: Andreas Braathen (mnemonic.io)
· 2023-11-14 · logsource: product=windows category=process_creation · 1ddaa9a4-eb0b-4398-a9fe-7b018f9e23db
Detects exploitation attempt of CVE-2023-22518 (Confluence Data Center / Confluence Server), where an attacker can exploit vulnerable endpoints to e.g. create admin accounts and execute arbitrary commands.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2023-01-02 · logsource: product=windows category=process_creation · 20a5ffa1-3848-4584-b6f8-c7c7fd9f69c8
Detects execution of ruby using the "-e" flag. This is could be used as a way to launch a reverse shell or execute live ruby code.
Author: Tim Rauch (rule), Elastic (idea)
· 2022-10-17 · logsource: product=macos category=process_creation · 234dc5df-40b5-49d1-bf53-0d44ce778eca
Detects when a built-in utility is used to decode and decrypt a payload after a macOS disk image (DMG) is executed. Malware authors may attempt to evade detection and trick users into executing malicious code by encoding and encrypting their payload and placing it in a disk image file. This behavior is consistent with adware or malware families such as Bundlore and Shlayer.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2023-06-14 · logsource: product=windows category=process_creation · 236d8e89-ed95-4789-a982-36f4643738ba
Detects execution of the "VMwareToolBoxCmd.exe" with the "script" and "set" flag to setup a specific script that's located in a potentially suspicious location to run for a specific VM state
Author: Nasreddine Bencherchali (Nextron Systems), X__Junior (Nextron Systems)
· 2024-01-11 · logsource: product=windows category=process_creation · 2433a154-bb3d-42e4-86c3-a26bdac91c45
Detects the execution of a renamed "PingCastle" binary based on the PE metadata fields.
All 95 rules on the technique page →
T1190 Exploit Public-Facing Application exploitation technique
- DET0080 Exploit Public-Facing Application – multi-signal correlation (request → error → post-exploit process/egress)
AN0219 WindowsAdversary sends crafted HTTP/S (or other service) input to an Internet-facing app (IIS/ASP.NET, API, device portal). Chain: (1) abnormal request patterns to public endpoint → (2) elevated 4xx/5xx or unusual methods/paths → (3) server process (w3wp.exe/other service) spawns shell/LOLbins or loads non-standard modules → (4) optional outbound callback from the host/container.ApplicationLog:IIS
IIS W3C logs in C:\inetpub\logs\LogFiles\W3SVC* (spikes in 5xx, RCE/SQLi/path traversal/JNDI patterns)→ DC0038 Application Log ContentTunable:PublicVIPsSuspiciousPatternsErrorRateThresholdTimeWindowAllowedChildListAN0220 LinuxAdversary exploits Apache/Nginx/app servers. Chain: (1) suspicious requests in access logs → (2) spike of 5xx or WAF blocks → (3) web server or interpreter (apache2/nginx/php-fpm/node/python) spawns /bin/sh, curl, wget, socat, or writes webshell → (4) outbound callback.ApplicationLog:WebServer/var/log/httpd/access_log, /var/log/apache2/access.log, /var/log/nginx/access.log with exploit indicators and burst errors→ DC0038 Application Log ContentNSM:FlowHTTP payloads with SQLi/LFI/JNDI/deserialization indicators→ DC0085 Network Traffic ContentTunable:WebProcListChildToolListBurstThresholdTimeWindowAN0221 macOSAdversary targets macOS-hosted public services (e.g., nginx, node). Chain: suspicious inbound request → service crash/5xx → service spawns shell or writes file → new outbound connection.macos:unifiedlogApp/web server logs ingested via unified logging or filebeat (nginx/apache/node).→ DC0038 Application Log ContentTunable:ServiceListTimeWindowAN0222 ContainersAdversary exploits containerized app via ingress or service. Chain: (1) suspicious request in ingress/app logs → (2) container process spawns a shell/exec/sidecar (kubectl exec/docker exec) → (3) egress to Internet or metadata service (169.254.169.254).ApplicationLog:IngressKubernetes NGINX/Envoy ingress controller logs with anomalous payloads and 5xx spikes→ DC0038 Application Log Contentdocker:eventsDocker/Kubernetes audit of exec/attach (kubectl exec) or unexpected child processes inside container→ DC0032 Process CreationNSM:FlowRequests towards cloud metadata or command & control from pod IPs→ DC0085 Network Traffic ContentTunable:IngressNamespacesMetadataEndpointsTimeWindowAN0223 IaaSAdversary targets cloud-hosted public endpoints. Chain: (1) ALB/ELB/Cloud LB logs show exploit-like inputs or error spikes → (2) workload spawns shell or reaches metadata API → (3) egress to new external hosts.ALB:HTTPLogsAWS ALB/ELB/GCP/Azure Application Gateway HTTP logs with unusual methods, long URIs, serialized payloads, 4xx/5xx bursts→ DC0085 Network Traffic ContentAWS:VPCFlowLogsVPC/NSG flow logs for pod/instance egress to Internet or metadata→ DC0078 Network Traffic FlowTunable:LBProjectsErrorBurstAN0224 ESXiAdversary exploits exposed OpenSLP on ESXi or vCenter public endpoints. Chain: inbound request pattern to mgmt service → hostd/vpxd error/crash/restart → unexpected process behavior or datastore access → outbound callback.esxi:hostd/var/log/hostd.log anomalies (faults, crashes, restarts) around inbound connections→ DC0038 Application Log ContentNSM:FlowConnections to TCP 427 (SLP) or vCenter web services from untrusted sources→ DC0085 Network Traffic ContentTunable:MgmtCIDRTimeWindowAN0225 Network DevicesAdversary exploits public admin services on routers/firewalls/switches. Chain: anomalous HTTP/SNMP/SmartInstall inputs → device syslog errors/restarts → config changes/CLI spawn → egress to attacker C2.networkdevice:controlplaneSyslog from edge devices with HTTP 500s on mgmt portal, SmartInstall events, unexpected CLI commands→ DC0038 Application Log ContentTunable:MgmtPortsTrustedAdmins
Sigma rules tagged attack.t1190 (149)
Author: Nasreddine Bencherchali (Nextron Systems)
· 2023-05-30 · logsource: category=webserver · 043c1609-0e32-4462-a6f2-5a0c2da3fafe
Detects a potential exploitation attempt of CVE-2023-25717 a Remote Code Execution via an unauthenticated HTTP GET Request, in Ruckus Wireless Admin
Author: @gott_cyber
· 2022-12-11 (modified 2023-03-24) · logsource: category=webserver · 0bbcd74b-0596-41a4-94a0-4e88a76ffdb3
Detects exploitation attempt of the CVE-2021-27905 which affects all Apache Solr versions prior to and including 8.8.1.
Author: Florian Roth (Nextron Systems)
· 2020-07-10 (modified 2023-01-02) · logsource: category=webserver · 0d0d9a8a-a49e-4e27-b061-7ce4b936cfb7
Detects exploitation attempt against Citrix Netscaler, Application Delivery Controller (ADS) and Citrix Gateway exploiting vulnerabilities reported as CVE-2020-8193 and CVE-2020-8195
Author: Thomas Patzke
· 2017-08-06 (modified 2020-09-01) · logsource: product=ruby_on_rails category=application · 0d2c3d4c-4b48-4ac3-8f23-ea845746bb1a
Detects suspicious Ruby on Rails exceptions that could indicate exploitation attempts
Author: Bhabesh Raj
· 2023-02-23 · logsource: category=webserver · 0e1ebc5a-15d0-4bf6-8199-b2535397433a
Detects the potential exploitation attempt of CVE-2023-23752 an Improper access check, in web service endpoints in Joomla
Author: Nisarg Suthar
· 2025-08-01 · logsource: product=windows category=process_creation · 0fdc7c7f-c690-4217-9ae3-31f5156eed72
Detects suspicious child processes created by CrushFTP. It could be an indication of exploitation of a RCE vulnerability such as CVE-2025-54309.
Author: Florian Roth (Nextron Systems)
· 2019-05-22 (modified 2023-01-25) · logsource: product=windows category=process_creation · 1012f107-b8f1-4271-af30-5aed2de89b39
Detects a process spawned by the terminal service server process (this could be an indicator for an exploitation of CVE-2019-0708)
Author: jamesc-grafana
· 2024-07-11 · logsource: product=aws service=cloudtrail · 14f3f1c8-02d5-43a2-a191-91ffb52d3015
Detects changes to the security group entries for RDS databases.
This can indicate that a misconfiguration has occurred which potentially exposes the database to the public internet, a wider audience within the VPC or that removal of valid rules has occurred which could impact the availability of the database to legitimate services and users.
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
· 2025-11-20 · logsource: category=proxy · 15697955-6a29-47ca-92e9-0e05efae3260
Detects suspicious requests to Cisco ASA WebVpn via proxy logs associated with CVE-2025-20333 and CVE-2025-20362 exploitation.
Author: Bhabesh Raj
· 2021-01-25 (modified 2023-01-02) · logsource: category=webserver · 15c312b9-00d0-4feb-8870-7d940a4bdc5e
Detects the exploitation of the TerraMaster TOS vulnerability described in CVE-2020-28188
Author: Moti Harmats
· 2023-02-11 · logsource: product=velocity category=application · 16c86189-b556-4ee8-b4c7-7e350a195a4f
Detects exceptions in velocity template renderer, this most likely happens due to dynamic rendering of user input and may lead to RCE.
Author: Bhabesh Raj
· 2021-02-24 (modified 2023-01-02) · logsource: category=webserver · 179ed852-0f9b-4009-93a7-68475910fd86
Detects the exploitation of VSphere Remote Code Execution vulnerability as described in CVE-2021-21972
Author: Nasreddine Bencherchali (Nextron Systems)
· 2022-12-22 (modified 2023-01-02) · logsource: category=webserver · 181f49fa-0b21-4665-a98c-a57025ebb8c7
Detects exploitation attempt of the OWASSRF variant targeting exchange servers It uses the OWA endpoint to access the powershell backend endpoint
Author: Nasreddine Bencherchali (Nextron Systems), Tim Shelton
· 2022-07-19 (modified 2026-06-11) · logsource: category=webserver · 19aa4f58-94ca-45ff-bc34-92e533c0994a
Detects known suspicious (default) user-agents related to scanning/recon tools
Author: Thomas Patzke
· 2017-08-12 (modified 2020-09-01) · logsource: product=python category=application · 19aefed0-ffd4-47dc-a7fc-f8b1425e84f9
Generic rule for SQL exceptions in Python according to PEP 249
All 149 rules on the technique page →
Sigma rules tagged with this CVE directly
1 rule carries cve.2021-22893.
Author: Sittikorn S
· 2021-06-29 (modified 2023-01-02) · logsource: category=webserver · 5525edac-f599-4bfd-b926-3fa69860e766
This rule detects exploitation attempts using Pulse Connect Secure(PCS) vulnerability (CVE-2021-22893)