Web server requests targeting WebLogic JNDI LDAP via JndiBindingHandle (CVE-2021-2109)

Alerts on GET requests with WebLogic JndiBindingHandle and an ldap:// payload targeting AdminServer.

FreeReviewedSigma · Critical · v5

Category: webserver
Author: Bhabesh Raj (SigmaHQ), DRL 1.1
Published: 2021-01-20
Updated: 2026-07-31

ATT&CK techniques

Initial Access

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags HTTP GET requests whose query string contains WebLogic-specific JNDI binding parameters along with an LDAP reference and an AdminServer identifier. Such requests are characteristic of attempts to exploit the WebLogic JNDI/LDAP pathway associated with CVE-2021-2109. It relies on webserver telemetry capturing the HTTP method and full URI query string content, enabling detection of injection-style payloads embedded in requests.

Reporting behind it

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Web server requests targeting WebLogic JNDI LDAP via JndiBindingHandle (CVE-2021-2109)

Pivot detection · T1190 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

webserver-detection-weblogic-jndibindinghandle-ldap-probe-cve-2021-2109-687f6504

title: Web server requests targeting WebLogic JNDI LDAP via JndiBindingHandle (CVE-2021-2109)
id: fa3c0e09-215c-4964-bb5b-f7836aefb9b6
status: test
description: This rule flags HTTP GET requests whose query string contains WebLogic-specific JNDI binding parameters along with an LDAP reference and an AdminServer identifier. Such requests are characteristic of attempts to exploit the WebLogic JNDI/LDAP pathway associated with CVE-2021-2109. It relies on webserver telemetry capturing the HTTP method and full URI query string content, enabling detection of injection-style payloads embedded in requests.
references:
  - https://twitter.com/pyn3rd/status/1351696768065409026
  - https://mp.weixin.qq.com/s/wX9TMXl1KVWwB_k6EZOklw
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Exploits/CVE-2021-2109/web_cve_2021_2109_weblogic_rce_exploit.yml
author: Bhabesh Raj, Huntrule Team
date: 2021-01-20
modified: 2023-01-02
tags:
  - attack.t1190
  - attack.initial-access
  - cve.2021-2109
  - detection.emerging-threats
logsource:
  category: webserver
detection:
  selection:
    cs-method: GET
    cs-uri-query|contains|all:
      - com.bea.console.handles.JndiBindingHandle
      - ldap://
      - AdminServer
  condition: selection
falsepositives:
  - Unknown
level: critical
license: DRL-1.1
related:
  - id: 687f6504-7f44-4549-91fc-f07bab065821
    type: derived

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