CVE-2017-17042: Yard Arbitrary File Read Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-gj4p-3wh3-2rmf
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CVSS 7.5
CWE-22
Published
Advisory Summary

CVE-2017-17042 is a HIGH (CVSS 7.5) arbitrary file read vulnerability vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Yard libraries in the RubyGems ecosystem. The issue involves arbitrary file read vulnerability in yard server. Remediation is available by upgrading affected packages to version 0.9.11.

CVE-2017-17042 at a Glance

CVE Identifier CVE-2017-17042
GHSA Identifier GHSA-gj4p-3wh3-2rmf
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Yard
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

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

How to Fix CVE-2017-17042

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

yard fixed: 0.9.11 
Upgrade yard to 0.9.11
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 yard

How to Check if You Are Affected

To determine whether your application is affected by CVE-2017-17042, inspect your project dependencies for Yard:

inspect dependencies for yard

Analyze the terminal output to locate any version of Yard in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.11), 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 Yard, 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

`lib/yard/core_ext/file.rb` in the server in YARD before 0.9.11 does not block relative paths with an initial `../` sequence, which allows attackers to conduct directory traversal attacks and read arbitrary files.

CVE-2017-17042 Affected Yard Versions

1 component(s)
Fixed Versions:
0.9.11
Product / Package Ecosystem Affected Versions Fixed Version
yard
gem/yard
RubyGems
< 0.9.11
0.9.11

References

NVD — CVE-2017-17042 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-17042
Security Fix Commit FIX COMMIT
https://github.com/lsegal/yard/commit/b0217b3e30dc53d057b1682506333335975e62b4
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-gj4p-3wh3-2rmf
Yard Source Repository REPOSITORY
https://github.com/lsegal/yard
Yard Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/yard/CVE-2017-17042.yml

Frequently Asked Questions

What is CVE-2017-17042?
CVE-2017-17042 is a security vulnerability in Yard involving Arbitrary file read vulnerability in yard server under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Yard versions are affected?
Affected versions include releases prior to 0.9.11 across affected packages: yard.
What version fixes CVE-2017-17042?
Upgrading to 0.9.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is yard affected?
Yes, yard is affected in releases prior to 0.9.11. Upgrade your dependency to 0.9.11 or later.
What is the CVSS score of CVE-2017-17042?
CVE-2017-17042 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2017-17042?
CVE-2017-17042 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 RubyGems dependencies for CVE-2017-17042?
Run the dependency tree command: 'inspect dependencies for yard'. 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-gj4p-3wh3-2rmf",
  "modified" : "2023-07-05T17:53:08Z",
  "published" : "2017-12-21T00:47:25Z",
  "aliases" : [ "CVE-2017-17042" ],
  "summary" : "Arbitrary file read vulnerability in yard server",
  "details" : "`lib/yard/core_ext/file.rb` in the server in YARD before 0.9.11 does not block relative paths with an initial `../` sequence, which allows attackers to conduct directory traversal attacks and read arbitrary files.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "yard"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-17042"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lsegal/yard/commit/b0217b3e30dc53d057b1682506333335975e62b4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-gj4p-3wh3-2rmf"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/lsegal/yard"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/yard/CVE-2017-17042.yml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:37:31Z",
    "nvd_published_at" : null
  }
}