CVE-2021-36157: Github.com/cortexproject/cortex Path Traversal Vulnerability

MODERATE
Advisory Identifier: GHSA-jphm-g89m-v42p
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CWE-22
Published
Advisory Summary

CVE-2021-36157 is a MODERATE path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Github.com/cortexproject/cortex libraries in the Go ecosystem. The issue involves path traversal in grafana cortex. Remediation is available in the latest vendor maintenance releases.

CVE-2021-36157 at a Glance

CVE Identifier CVE-2021-36157
GHSA Identifier GHSA-jphm-g89m-v42p
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Github.com/cortexproject/cortex
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2021-36157

To remediate this vulnerability, upgrade all affected Github.com/cortexproject/cortex dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/cortexproject/cortex fixed: Latest secure release 
Upgrade github.com/cortexproject/cortex to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/cortexproject/cortex

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-36157, inspect your project dependencies for Github.com/cortexproject/cortex:

inspect dependencies for github.com/cortexproject/cortex

Analyze the terminal output to locate any version of Github.com/cortexproject/cortex in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Github.com/cortexproject/cortex, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An issue was discovered in Grafana Cortex through 1.9.0. The header value X-Scope-OrgID is used to construct file paths for rules files, and if crafted to conduct directory traversal such as ae ../../sensitive/path/in/deployment pathname, then Cortex will attempt to parse a rules file at that location and include some of the contents in the error message. (Other Cortex API requests can also be sent a malicious OrgID header, e.g., tricking the ingester into writing metrics to a different location, but the effect is nuisance rather than information disclosure.)

CVE-2021-36157 Affected Github.com/cortexproject/cortex Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cortexproject/cortex
golang/github.com/cortexproject/cortex
Go
≤ 1.9.0

References

NVD — CVE-2021-36157 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-36157
Github.com/cortexproject/cortex Source Repository REPOSITORY
https://github.com/cortexproject/cortex/pull/4375
Security Fix Commit FIX COMMIT
https://github.com/cortexproject/cortex/commit/d9e1f81f40c607b9e97c2fc6db70ae54679917c4
Github.com/cortexproject/cortex Source Repository REPOSITORY
https://github.com/cortexproject/cortex
grafana.com/docs/grafana/latest... WEB
https://grafana.com/docs/grafana/latest/release-notes

Frequently Asked Questions

What is CVE-2021-36157?
CVE-2021-36157 is a security vulnerability in Github.com/cortexproject/cortex involving Path traversal in Grafana Cortex under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Github.com/cortexproject/cortex versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/cortexproject/cortex.
What version fixes CVE-2021-36157?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cortexproject/cortex affected?
Yes, github.com/cortexproject/cortex is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with CVE-2021-36157?
CVE-2021-36157 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Go dependencies for CVE-2021-36157?
Run the dependency tree command: 'inspect dependencies for github.com/cortexproject/cortex'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jphm-g89m-v42p",
  "modified" : "2021-08-30T23:21:48Z",
  "published" : "2021-09-02T21:59:50Z",
  "aliases" : [ "CVE-2021-36157" ],
  "summary" : "Path traversal in Grafana Cortex",
  "details" : "An issue was discovered in Grafana Cortex through 1.9.0. The header value X-Scope-OrgID is used to construct file paths for rules files, and if crafted to conduct directory traversal such as ae ../../sensitive/path/in/deployment pathname, then Cortex will attempt to parse a rules file at that location and include some of the contents in the error message. (Other Cortex API requests can also be sent a malicious OrgID header, e.g., tricking the ingester into writing metrics to a different location, but the effect is nuisance rather than information disclosure.)",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cortexproject/cortex"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-36157"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cortexproject/cortex/pull/4375"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cortexproject/cortex/commit/d9e1f81f40c607b9e97c2fc6db70ae54679917c4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cortexproject/cortex"
  }, {
    "type" : "WEB",
    "url" : "https://grafana.com/docs/grafana/latest/release-notes"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-04T18:31:56Z",
    "nvd_published_at" : "2021-08-03T15:15:00Z"
  }
}