CVE-2021-41277

The vulnerability in the open-source data analytics platform Metabase stems from inadequate validation of URLs when handling custom GeoJSON maps. This security issue allows an attacker to potentially exploit local file inclusion vulnerabilities, which can lead to unauthorized access to sensitive files, including environment variables. The flaw exists in versions prior to the maintenance release 0.40.5 and 1.40.5, where the application fails to properly sanitize inputs associated with the custom maps feature. As a result, malicious actors could craft specially designed URLs that, when processed by the application, might lead to the exposure of critical system files or sensitive data.

Exploitation of this vulnerability can occur through various attack vectors. An attacker could leverage social engineering tactics to trick users into clicking on a malicious link that initiates the loading of a crafted GeoJSON map. Alternatively, if an attacker has access to the Metabase instance, they could directly manipulate the map settings to include harmful URLs. Once the application processes these URLs, it could inadvertently expose local files or environment variables, leading to further exploitation. This could facilitate a range of attacks, including data theft, system compromise, or lateral movement within the network, depending on the permissions of the compromised application.

The real-world impact of this vulnerability is significant, particularly for organizations that rely on Metabase for data analytics and reporting. The exposure of sensitive files could lead to data breaches, regulatory penalties, and reputational damage. For instance, if environment variables containing database credentials or API keys are compromised, attackers could gain unauthorized access to critical systems, resulting in severe operational disruptions. The business risk is compounded by the potential for attackers to leverage the information obtained through exploitation to launch further attacks, thereby increasing the overall threat landscape for the organization.

To detect and mitigate this vulnerability, organizations should prioritize upgrading to the patched versions of Metabase as soon as possible. In scenarios where immediate upgrades are not feasible, implementing security measures at the network level is crucial. This includes configuring reverse proxies, load balancers, or web application firewalls (WAF) to enforce strict validation rules for incoming URLs. By filtering out potentially harmful requests before they reach the application, organizations can significantly reduce the risk of exploitation. Additionally, regular security assessments and code reviews should be conducted to identify and remediate similar vulnerabilities proactively.

In conclusion, the vulnerability in Metabase highlights the critical importance of input validation in web applications, particularly those handling user-generated content. The potential for local file inclusion poses serious risks to data integrity and confidentiality, necessitating a robust security posture. Organizations must remain vigilant, ensuring timely updates and implementing layered security controls to protect against such vulnerabilities. By fostering a culture of security awareness and proactive risk management, businesses can better safeguard their assets and maintain trust with stakeholders.

CSURFACE threat intelligence has detected a marked escalation in activity related to CVE-2021-41277, with telemetry indicating a significant uptick in exploitation attempts targeting vulnerable Metabase instances. This surge coincides with the recent inclusion of the vulnerability in the Known Exploited Vulnerabilities (KEV) catalog, which likely increased attacker focus and scanning efforts. Although the Exploit Prediction Scoring System (EPSS) score remains high but stable, the proliferation of publicly available proof-of-concept exploits has lowered the barrier for adversaries to weaponize this flaw. The increased exploitation activity underscores the heightened risk to organizations running unpatched versions of Metabase, as successful exploitation can lead to local file inclusion and potential exposure of sensitive environment variables. Consequently, the threat level has escalated from elevated concern to a more urgent posture, emphasizing the need for defenders to prioritize detection and response capabilities around this vulnerability.

Update 2 — May 20, 2026

CSURFACE threat intelligence has observed a marked escalation in the criticality assessment of CVE-2021-41277, reflected by the CVSS score increase from 7.5 to the maximum 10.0. This adjustment follows its recent inclusion in the KEV catalog, underscoring the vulnerability’s heightened priority for remediation. Despite a significant reduction in detection activity across our telemetry, the availability of multiple proof-of-concept exploits on public repositories continues to lower the barrier for adversaries to weaponize this flaw. The elevated CVSS score signals an increased potential impact, particularly given the vulnerability’s capacity for local file inclusion and exposure of sensitive environment variables within Metabase instances. While ransomware usage remains unconfirmed, the critical severity and ease of exploitation maintain this vulnerability as a high-risk target for threat actors. Consequently, the overall threat level has shifted to critical, emphasizing the urgency for defenders to enhance monitoring and incident response capabilities related to this vulnerability.

Update 3 — June 07, 2026

CSURFACE threat intelligence has detected a marked escalation in exploitation attempts targeting CVE-2021-41277, accompanied by the emergence of multiple new proof-of-concept exploits circulating on public repositories. This increased adversary activity underscores a growing interest in weaponizing the vulnerability, particularly given its critical severity and the potential for local file inclusion leading to sensitive environment variable disclosure. Although ransomware involvement remains unconfirmed, the surge in exploitation efforts elevates the likelihood of this vulnerability being leveraged in broader attack campaigns. Consequently, the threat level associated with CVE-2021-41277 has intensified, warranting heightened vigilance from defenders monitoring Metabase environments and related telemetry.

Update 4 — July 05, 2026

CSURFACE threat intelligence has identified a marked escalation in exploitation attempts targeting CVE-2021-41277, accompanied by a modest upward revision of its CVSS score to 7.5. This adjustment reflects a refined understanding of the vulnerability’s impact, particularly concerning the local file inclusion vector that can expose sensitive environment variables. Concurrently, our telemetry indicates a sustained increase in adversary interest, as evidenced by the proliferation of new proof-of-concept exploits publicly available on code-sharing platforms. Although ransomware usage linked to this vulnerability remains unconfirmed, the expanding exploit toolkit and rising EPSS score underscore an elevated risk of broader operationalization. For defenders, this evolving threat landscape signifies a heightened urgency to monitor Metabase deployments closely, as the vulnerability’s exploitation potential is becoming more accessible and attractive to a wider range of threat actors. Consequently, the overall threat level for CVE-2021-41277 has intensified, warranting increased vigilance and prioritization within vulnerability management programs.