CVE-2021-3907: Github.com/cloudflare/cfrpki Path Traversal Vulnerability

HIGH
Advisory Identifier: GHSA-cqh2-vc2f-q4fh
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CVSS 7.4
CWE-20 CWE-22
Published
Advisory Summary

CVE-2021-3907 is a HIGH (CVSS 7.4) path traversal vulnerability (CWE-20: Improper Input Validation) affecting Github.com/cloudflare/cfrpki libraries in the Go ecosystem. The issue involves arbitrary filepath traversal via uri injection. Remediation is available by upgrading affected packages to version 1.4.4.

CVE-2021-3907 at a Glance

CVE Identifier CVE-2021-3907
GHSA Identifier GHSA-cqh2-vc2f-q4fh
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-20: Improper Input Validation
Affected Product Github.com/cloudflare/cfrpki
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-3907

To remediate this vulnerability, upgrade all affected Github.com/cloudflare/cfrpki 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/cloudflare/cfrpki fixed: 1.4.4 
Upgrade github.com/cloudflare/cfrpki to 1.4.4
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/cloudflare/cfrpki

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-3907, inspect your project dependencies for Github.com/cloudflare/cfrpki:

inspect dependencies for github.com/cloudflare/cfrpki

Analyze the terminal output to locate any version of Github.com/cloudflare/cfrpki in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.4), 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-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Github.com/cloudflare/cfrpki, 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

OctoRPKI does not escape a URI with a filename containing "..", this allows a repository to create a file, (ex. `rsync://example.org/repo/../../etc/cron.daily/evil.roa`), which would then be written to disk outside the base cache folder. This could allow for remote code execution on the host machine OctoRPKI is running on. ## Patches ## For more information If you have any questions or comments about this advisory email us at security@cloudflare.com

CVE-2021-3907 Affected Github.com/cloudflare/cfrpki Versions

1 component(s)
Fixed Versions:
1.4.4
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cloudflare/cfrpki
golang/github.com/cloudflare/cfrpki
Go
< 1.4.4
1.4.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-3jhm-87m6-x959
GitHub Advisory / Wiki ADVISORY
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-cqh2-vc2f-q4fh
NVD — CVE-2021-3907 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-3907
Security Fix Commit FIX COMMIT
https://github.com/cloudflare/cfrpki/commit/a053a808feeb3115c76b6cc263ee55598ce6e8cd
Security Fix Commit FIX COMMIT
https://github.com/cloudflare/cfrpki/commit/eb9cc4db7b7b79e44f56dfaa959fccdfb2af8284
Github.com/cloudflare/cfrpki Source Repository REPOSITORY
https://github.com/cloudflare/cfrpki
pkg.go.dev/vuln/go-2022-0248 WEB
https://pkg.go.dev/vuln/GO-2022-0248
Github.com/cloudflare/cfrpki Security Information SECURITY
https://www.debian.org/security/2021/dsa-5033
Github.com/cloudflare/cfrpki Security Information SECURITY
https://www.debian.org/security/2022/dsa-5041

Frequently Asked Questions

What is CVE-2021-3907?
CVE-2021-3907 is a security vulnerability in Github.com/cloudflare/cfrpki involving Arbitrary filepath traversal via URI injection under CWE-20: Improper Input Validation.
Which Github.com/cloudflare/cfrpki versions are affected?
Affected versions include releases prior to 1.4.4 across affected packages: github.com/cloudflare/cfrpki.
What version fixes CVE-2021-3907?
Upgrading to 1.4.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cloudflare/cfrpki affected?
Yes, github.com/cloudflare/cfrpki is affected in releases prior to 1.4.4. Upgrade your dependency to 1.4.4 or later.
What is the CVSS score of CVE-2021-3907?
CVE-2021-3907 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H.
What CWE is associated with CVE-2021-3907?
CVE-2021-3907 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check Go dependencies for CVE-2021-3907?
Run the dependency tree command: 'inspect dependencies for github.com/cloudflare/cfrpki'. 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-cqh2-vc2f-q4fh",
  "modified" : "2021-11-10T18:16:54Z",
  "published" : "2021-11-10T20:08:29Z",
  "aliases" : [ "CVE-2021-3907" ],
  "summary" : "Arbitrary filepath traversal via URI injection ",
  "details" : "OctoRPKI does not escape a URI with a filename containing \"..\", this allows a repository to create a file, (ex.  `rsync://example.org/repo/../../etc/cron.daily/evil.roa`), which would then be written to disk outside the base cache folder. This could allow for remote code execution on the host machine OctoRPKI is running on. \n\n## Patches\n\n## For more information\nIf you have any questions or comments about this advisory email us at security@cloudflare.com\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cloudflare/cfrpki"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-3jhm-87m6-x959"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-cqh2-vc2f-q4fh"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3907"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/cfrpki/commit/a053a808feeb3115c76b6cc263ee55598ce6e8cd"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/cfrpki/commit/eb9cc4db7b7b79e44f56dfaa959fccdfb2af8284"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cloudflare/cfrpki"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2022-0248"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2021/dsa-5033"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2022/dsa-5041"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-11-10T18:16:54Z",
    "nvd_published_at" : "2021-11-11T22:15:00Z"
  }
}