CVE-2021-36157 : Vulnerability Insights and Analysis

An issue was discovered in Grafana Cortex through 1.9.0 where the header value X-Scope-OrgID can be manipulated to conduct directory traversal, potentially leading to parsing files at unintended locations and exposing sensitive information in error messages. It could also be exploited to trick the ingester into writing metrics to a different location, although the impact would be nuisance rather than information disclosure.

Understanding CVE-2021-36157

This section delves into the details of CVE-2021-36157.

What is CVE-2021-36157?

The vulnerability in Grafana Cortex allows attackers to manipulate the X-Scope-OrgID header to perform directory traversal attacks, potentially resulting in unauthorized access to sensitive files.

The Impact of CVE-2021-36157

Exploiting this vulnerability could lead to unauthorized access to sensitive files and potential data leakage, albeit the exploitation for redirecting metrics would result in a nuisance rather than a severe security breach.

Technical Details of CVE-2021-36157

Here, we explore the technical specifics of CVE-2021-36157.

Vulnerability Description

By manipulating the X-Scope-OrgID header, threat actors can conduct directory traversal attacks to access files at unintended locations, potentially exposing sensitive information.

Affected Systems and Versions

Grafana Cortex versions up to 1.9.0 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting the X-Scope-OrgID header to trick Cortex into parsing rules files at unauthorized locations, leading to potential data exposure.

Mitigation and Prevention

This section discusses the steps to mitigate and prevent CVE-2021-36157.

Immediate Steps to Take

Users are advised to update Grafana Cortex to a patched version that addresses the vulnerability. It is also recommended to restrict and sanitize input headers to prevent malicious manipulation.

Long-Term Security Practices

Implementing strict input validation and security controls, such as limiting file path access and applying the principle of least privilege, can help prevent similar vulnerabilities in the future.

Patching and Updates

Regularly monitoring security advisories from Grafana and applying timely updates and patches is crucial to ensure a secure environment.