Coordinated Exploitation Campaign Targets Grafana Vulnerability

Grafana, the widely used open-source analytics and visualization platform, is once again in the crosshairs of attackers. 

Security researchers recently detected a sharp spike in attempts to exploit a known path traversal vulnerability that enables arbitrary file reads on unpatched systems.  The sudden surge, which involved 110 unique malicious IP addresses in just one day, highlights the persistence of older but high-impact flaws in the wild.

GreyNoise researchers stated in a blog post, “We anticipate old vulnerabilities —  like CVE-2021-43798, and even older ones — will continue resurging in the future.”

Legacy flaws, lasting risks

The resurgence of CVE-2021-43798 matters because it demonstrates that legacy vulnerabilities continue to pose significant threats. 

Organizations that have not patched their Grafana deployments remain vulnerable to file disclosure attacks, where adversaries can extract sensitive configuration files and credentials. These compromises can cascade into deeper intrusions within monitoring environments and cloud infrastructure.

This is another reminder that patching and proactive monitoring remain critical pillars of defense. Unpatched systems — even against older CVEs — are frequent entry points in exploit chains.

Patterns in the campaign

CVE-2021-43798 is a path traversal flaw that permits arbitrary file reads. By manipulating traversal sequences in HTTP requests, attackers can force Grafana to return sensitive local files. For example, configuration data or system credentials may be exposed if the flaw is successfully exploited.

GreyNoise researchers observed uniform patterns in this campaign. Attack traffic targeted three destinations — the United States, Slovakia, and Taiwan — in a consistent 3:1:1 ratio across different source countries. Bangladesh accounted for most of scanning activity, with 107 IPs involved, while China and Germany contributed a handful of addresses.

Most of these IPs appeared on the same day they attempted exploitation, suggesting the use of disposable infrastructure. Analysts also noted convergence in tooling fingerprints, such as TLS JA3 hashes and User-Agent strings, indicating that operators were likely sharing kits or working from a common playbook.

Defensive priorities for security teams

To reduce exposure from this exploitation campaign, security teams should prioritize the following measures that combine patching, monitoring, and response readiness: 

• Update Grafana: Patch all instances to address CVE-2021-43798 immediately.
• Log review: Inspect web server logs for traversal requests and unauthorized file access.
• Block malicious IPs: Use dynamic blocklists with JA3/JA4 signature support to stop known attackers.
• Patch management: Treat older vulnerabilities with the same urgency as new zero-days.
• Segmentation and least privilege: Limit access in Grafana and related systems to reduce impact if compromised.
• Incident response: Maintain living playbooks and conduct tabletop exercises to ensure teams can respond quickly to attacks.

By combining timely patching with proactive monitoring and well-rehearsed response plans, organizations can stay resilient against emerging threats.

Old flaws, new campaigns

This activity illustrates a persistent trend: attackers are quick to recycle older, high-impact vulnerabilities because they remain effective. 

For example, path traversal flaws in Grafana have been integrated into server-side request forgery (SSRF) attacks and account takeover toolkits. Their appearance in reconnaissance stages of multi-step exploit chains also makes them dangerous.

GreyNoise does not attribute this activity to a specific group, but the alignment of geographies, ratios, and fingerprints strongly suggests centralized orchestration. Whether one operator is leveraging broad infrastructure or multiple actors are using the same exploit kit, the effect is the same: unpatched systems become low-hanging fruit.

Security teams should view this resurgence as a warning. The patch lifecycle must extend beyond headline-grabbing zero-day vulnerabilities to cover older, well-documented flaws. Otherwise, coordinated campaigns like this exploitation surge will continue to succeed.

As the researchers cautioned, exploitation of legacy flaws is not going away. Organizations that treat patching and monitoring as continuous, disciplined processes will be best positioned to withstand these attacks.

Strengthening patch management is important, but pairing it with a zero-trust approach ensures that even if attackers exploit older vulnerabilities, their ability to move laterally and escalate privileges is limited.