Coverage › CVE-2021-39226

CVE-2021-39226 Mapped Sigma

Grafana Authentication Bypass Vulnerability

Vendor / product

Grafana Labs — Grafana

Description (CISA)

Grafana contains an authentication bypass vulnerability that allows authenticated and unauthenticated users to view and delete all snapshot data, potentially resulting in complete snapshot data loss.

Added to KEV

2022-08-25

Due date

2022-09-15

Required action

Apply updates per vendor instructions.

Known ransomware use

Unknown

CWE

CWE-287

CISA notes

https://grafana.com/blog/2021/10/05/grafana-7.5.11-and-8.1.6-released-with-critical-security-fix/
https://nvd.nist.gov/vuln/detail/CVE-2021-39226

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

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 →

T1485 Data Destruction primary impact

• DET0146 Detection of Data Destruction Across Platforms via Mass Overwrite and Deletion Patterns
  AN0411 Windows

  Adversary spawns command-line tools (e.g., del, cipher /w, SDelete) or scripts to recursively delete or overwrite user/system files. This may be correlated with abnormal file IO activity, registry writes, or tampering in critical system directories.

  WinEventLog:Sysmon EventCode=1 → DC0032 Process Creation

  WinEventLog:Sysmon EventCode=11 → DC0039 File Creation

  WinEventLog:Sysmon EventCode=23 → DC0040 File Deletion

  Tunable: TargetFilename ProcessCommandLine VolumeThreshold TimeWindow
  AN0412 Linux

  Massive recursive deletions or overwrites via rm -rf, shred, dd, or wiper binaries. May include unlink syscalls, deletion of known config/data paths, or sequential overwrite patterns.

  auditd:SYSCALL unlink, unlinkat, openat, write → DC0040 File Deletion

  auditd:SYSCALL execve → DC0032 Process Creation

  Tunable: ExecutablePath DeletedPathPattern SyscallBurstRate
  AN0413 macOS

  Destruction via rm -rf, overwrite with dd or srm, often executed by script in /tmp or /private/tmp, may also involve file overwrite to political or decoy image data.

  macos:unifiedlog exec rm -rf|dd if=/dev|srm|file unlink → DC0040 File Deletion

  macos:unifiedlog process.*exit.*code → DC0033 Process Termination

  Tunable: CommandPattern EntropyChangeRate
  AN0414 IaaS

  Adversary deletes critical infrastructure: EC2 instances, S3 buckets, snapshots, or volumes using elevated IAM credentials. Frequently includes batch API calls with Delete* or TerminateInstances.

  AWS:CloudTrail DeleteBucket, DeleteDBCluster, DeleteSnapshot, TerminateInstances → DC0022 Cloud Storage Deletion

  Tunable: OperationType UserAgent RegionScope
  AN0415 ESXi

  Adversary destroys virtual disks (VMDK), images, or VMs by invoking vim-cmd, deleting datastore contents, or purging snapshots.

  esxi:vmkernel file delete|datastore purge → DC0098 Volume Deletion

  Tunable: DatastorePath InitiatingUser
  AN0416 Containers

  Container process executes destructive file operations inside volume mounts or host paths. Includes rm -rf /mnt/volumes/, container breakout followed by host deletion attempts.

  auditd:SYSCALL unlink, unlinkat, rmdir → DC0040 File Deletion

  docker:events container exec rm|container stop --force → DC0064 Command Execution

  Tunable: MountPoint ContainerImage

Sigma rules tagged attack.t1485 (20)

All 20 rules on the technique page →