CODE RED • ACTIVE EXPLOITATION SURGE

PATCH NOW: Coordinated Exploitation Surge Targets Grafana (CVE-2021-43798) Arbitrary File Read!

By CyberDudeBivash • October 04, 2025 • Urgent Security Directive

cyberdudebivash.com | cyberbivash.blogspot.com

Disclosure: This is an urgent security advisory for DevOps, SRE, and security professionals. It contains affiliate links to relevant security solutions. Your support helps fund our independent research.

Emergency Guide: Table of Contents

Chapter 1: The Threat — A Coordinated Attack on an Old Flaw

This is a code-red alert for all organizations using Grafana. Our threat intelligence feeds and public sources are reporting a massive, coordinated surge in scanning and exploitation activity targeting **CVE-2021-43798**. This is not a new vulnerability, which makes this event even more dangerous. It is a well-known, trivial-to-exploit path traversal flaw that gives an attacker a direct line to your server’s most sensitive files.

The current surge indicates that multiple threat actors have integrated this exploit into their automated toolkits and are actively compromising the “long tail” of unpatched Grafana instances that are still exposed to the internet. If you have not patched this vulnerability, you must assume you are being actively targeted right now.

Chapter 2: The Current Campaign — Who Is Attacking and What They Want

The attacks are opportunistic and automated. The goal of the attackers is to turn your unpatched server into a monetizable asset.

The Threat Actors:

Initial Access Brokers (IABs):** These are the most dangerous actors. They are compromising Grafana servers to steal credentials (database passwords, cloud API keys) and then selling this access to ransomware gangs on the dark web.
**Cryptomining Botnets:** These groups are using the exploit to gain code execution and install cryptocurrency miners, stealing your CPU cycles and racking up your electricity and cloud bills.

The Exploit in Action:

The attackers are using the path traversal to read critical configuration files. The primary targets are:

`conf/defaults.ini` & `conf/custom.ini`: To steal the `[database]` connection string and other secrets.
`/etc/passwd` & `/etc/shadow`: To gather local user information.
`/home/[user]/.ssh/id_rsa`: To steal SSH private keys.

Chapter 3: The Defender’s Playbook — A 3-Step Emergency Response

You must act immediately. This is an active incident.

Step 1: IDENTIFY and PATCH

Your first priority is to identify all Grafana instances in your organization. Check the version in the UI footer. Any version from 8.0.0-beta1 up to (but not including) 8.3.1 is **critically vulnerable**. You must **upgrade to the latest stable version immediately.**

Step 2: HUNT for Compromise

You must assume that any unpatched, internet-facing instance has already been compromised. The evidence is in your web server access logs. On your Grafana server, run this command:


grep -E "public/plugins/.*/\.{2}/" /var/log/grafana/grafana.log

If this command returns **any results**, your server has been targeted. You must immediately trigger your full incident response plan.

Step 3: ROTATE ALL SECRETS

If you were vulnerable and exposed, you must assume all secrets on the server have been stolen. **You must rotate all credentials immediately.** This includes the database password used by Grafana, all API keys stored in its configuration, and any SSH keys for the user running the Grafana service.

Chapter 4: The Strategic Lesson — You Must Master Asset Management

This exploitation surge is a brutal lesson in the importance of **asset and vulnerability management**. An old, forgotten, unpatched server is not a low risk; it is a ticking time bomb. Sophisticated security tools are useless if you fail at the most basic of security hygiene.

A mature security program requires:

**A Complete Asset Inventory:** You must have a real-time, comprehensive inventory of every piece of software and hardware in your environment. You cannot protect what you do not know you have.
**A Risk-Based Vulnerability Management Program:** You need a process to not just scan for vulnerabilities, but to prioritize and remediate them based on real-world exploitability and business impact, as we detailed in our **CVE WATCHDOG Framework**.

Detect the Next Step: Even if you miss the initial exploit, you must detect what the attacker does next. An **EDR platform** is your essential safety net to detect the lateral movement and post-exploitation activity that follows a breach like this.

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About the Author

CyberDudeBivash is a cybersecurity strategist with 15+ years in vulnerability management, incident response, and DevSecOps, advising CISOs across APAC. [Last Updated: October 04, 2025]

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