Coverage › CVE-2023-20198

CVE-2023-20198 Mapped Sigma

Cisco IOS XE Web UI Privilege Escalation Vulnerability

Vendor / product

Cisco — IOS XE Web UI

Description (CISA)

Cisco IOS XE Web UI contains a privilege escalation vulnerability in the web user interface that could allow a remote, unauthenticated attacker to create an account with privilege level 15 access. The attacker can then use that account to gain control of the affected device.

Added to KEV

2023-10-16

Due date

2023-10-20

Required action

Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.

Known ransomware use

Unknown

CWE

CWE-420

CISA notes

https://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-xe-dublin-17121/221128-software-fix-availability-for-cisco-ios.html
https://nvd.nist.gov/vuln/detail/CVE-2023-20198

Elsewhere

cve.org · NVD · CISA KEV · JSON

ATT&CK techniques · CTID Mappings Explorer, ATT&CK 16.1, KEV snapshot 2025-07-28

2 mapping objects across 2 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.

Detection chain · ATT&CK Enterprise v19.2 detection strategies, analytics, log sources

T1136 Create Account primary impact

• DET0583 Detection Strategy for T1136 - Create Account across platforms
  AN1604 Windows

  Adversary uses built-in OS tools or API calls to create local or domain accounts for persistence or lateral movement. Tools such as 'net user', PowerShell, or MMC snap-ins may be used. Detection focuses on Event ID 4720 paired with process lineage and user context.

  WinEventLog:Security EventCode=4720 → DC0014 User Account Creation

  WinEventLog:Sysmon EventCode=1 → DC0032 Process Creation

  Tunable: TimeWindow ParentProcessName UserContext
  AN1605 Linux

  Adversary invokes 'useradd', 'adduser', or equivalent system commands or scripts to create local users. Detection focuses on command execution and audit trail of passwd/shadow file modifications.

  auditd:SYSCALL useradd or adduser executed → DC0014 User Account Creation

  auditd:SYSCALL chmod/chown to /etc/passwd or /etc/shadow → DC0061 File Modification

  Tunable: BinaryPath ExecutionTime
  AN1606 macOS

  Adversary creates new users using 'dscl' commands, GUI tools, or by modifying user plist files. Detection includes monitoring dscl invocation and user-related plist changes.

  macos:unifiedlog dscl . -create → DC0064 Command Execution

  macos:unifiedlog modification to /var/db/dslocal/nodes/Default/users/ → DC0061 File Modification

  Tunable: UsernamePattern ExecutionSource
  AN1607 Identity Provider

  Adversary creates users via IAM/IdP API or portal (e.g., Azure AD, Okta). Detection involves monitoring API calls, admin action logs, and correlation with role assignments.

  azure:audit Add user → DC0014 User Account Creation

  Tunable: AdminThreshold AutomationExemptions
  AN1608 IaaS

  Account creation via cloud service APIs or CLI, often associated with key generation. Monitored via CloudTrail or equivalent audit logs.

  AWS:CloudTrail CreateUser → DC0014 User Account Creation

  AWS:CloudTrail AttachUserPolicy → DC0010 User Account Modification

  Tunable: Region ServiceScope

Sigma rules tagged attack.t1136 (3)

T1190 Exploit Public-Facing Application exploitation technique

• DET0080 Exploit Public-Facing Application – multi-signal correlation (request → error → post-exploit process/egress)
  AN0219 Windows

  Adversary 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 Content

  WinEventLog:Sysmon EventCode=1 → DC0032 Process Creation

  WinEventLog:Sysmon EventCode=7 → DC0016 Module Load

  WinEventLog:Sysmon EventCode=3, 22 → DC0082 Network Connection Creation

  Tunable: PublicVIPs SuspiciousPatterns ErrorRateThreshold TimeWindow AllowedChildList
  AN0220 Linux

  Adversary 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 Content

  auditd:SYSCALL execve → DC0032 Process Creation

  NSM:Flow HTTP payloads with SQLi/LFI/JNDI/deserialization indicators → DC0085 Network Traffic Content

  Tunable: WebProcList ChildToolList BurstThreshold TimeWindow
  AN0221 macOS

  Adversary 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:unifiedlog App/web server logs ingested via unified logging or filebeat (nginx/apache/node). → DC0038 Application Log Content

  macos:unifiedlog exec events where web process starts a shell/tooling → DC0032 Process Creation

  NSM:Flow outbound egress from web host after suspicious request → DC0085 Network Traffic Content

  Tunable: ServiceList TimeWindow
  AN0222 Containers

  Adversary 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:Ingress Kubernetes NGINX/Envoy ingress controller logs with anomalous payloads and 5xx spikes → DC0038 Application Log Content

  docker:events Docker/Kubernetes audit of exec/attach (kubectl exec) or unexpected child processes inside container → DC0032 Process Creation

  NSM:Flow Requests towards cloud metadata or command & control from pod IPs → DC0085 Network Traffic Content

  Tunable: IngressNamespaces MetadataEndpoints TimeWindow
  AN0223 IaaS

  Adversary 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:HTTPLogs AWS ALB/ELB/GCP/Azure Application Gateway HTTP logs with unusual methods, long URIs, serialized payloads, 4xx/5xx bursts → DC0085 Network Traffic Content

  AWS:VPCFlowLogs VPC/NSG flow logs for pod/instance egress to Internet or metadata → DC0078 Network Traffic Flow

  Tunable: LBProjects ErrorBurst
  AN0224 ESXi

  Adversary 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 Content

  NSM:Flow Connections to TCP 427 (SLP) or vCenter web services from untrusted sources → DC0085 Network Traffic Content

  Tunable: MgmtCIDR TimeWindow
  AN0225 Network Devices

  Adversary 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:controlplane Syslog from edge devices with HTTP 500s on mgmt portal, SmartInstall events, unexpected CLI commands → DC0038 Application Log Content

  NSM:Flow NetFlow/sFlow for odd egress to Internet from mgmt plane → DC0085 Network Traffic Content

  Tunable: MgmtPorts TrustedAdmins

Sigma rules tagged attack.t1190 (149)

All 149 rules on the technique page →