Multiple Vulnerabilities in Prometheus Allow for DoS, Information Disclosure, and XSS

A recent advisory highlights the presence of multiple vulnerabilities within Prometheus, a widely-used open-source monitoring and alerting toolkit. The vulnerabilities, if exploited, could permit a malicious actor to conduct a Denial of Service (DoS) attack, potentially disrupting monitoring services and impacting operational visibility. Furthermore, the flaws may facilitate the unauthorized disclosure of sensitive information handled by Prometheus. Finally, cross-site scripting (XSS) attacks are possible, potentially enabling attackers to execute malicious scripts within the context of legitimate user sessions. The vendor, Prometheus, has been notified, but details on specific versions affected or patch availability are currently unavailable.

Attack Chain

1. Attacker identifies a vulnerable Prometheus instance.
2. The attacker crafts a malicious request designed to exploit a specific vulnerability (DoS, information disclosure, or XSS).
3. For DoS, the attacker sends a series of resource-intensive requests that overwhelm the Prometheus server, causing it to become unresponsive.
4. For information disclosure, the attacker exploits a vulnerability to bypass access controls and gain access to sensitive data stored or managed by Prometheus, such as configuration files or metrics.
5. For XSS, the attacker injects malicious JavaScript code into a Prometheus page or data stream.
6. When a user interacts with the compromised page or data, the injected script executes within their browser, potentially stealing cookies, redirecting to malicious sites, or performing other unauthorized actions.

Impact

Successful exploitation of these vulnerabilities could lead to significant disruptions of monitoring and alerting capabilities within an organization’s infrastructure, leading to delayed incident response. Sensitive information disclosure could expose internal configurations or metrics, potentially aiding further attacks. Cross-site scripting could compromise user accounts and systems interacting with Prometheus web interfaces. The number of potential victims is dependent on the deployment size and security posture of Prometheus instances globally.

Recommendation

• Monitor webserver logs for suspicious requests targeting Prometheus web interfaces using the “Prometheus Suspicious Request” Sigma rule to identify potential exploitation attempts.
• Deploy the “Prometheus XSS Attempt” Sigma rule to detect potential XSS attacks.
• Closely monitor Prometheus server resource utilization (CPU, memory) for anomalies indicative of a denial-of-service attack (DoS).