CVE-2018-17567: Jekyll Jekyll Allows Attackers To Access Vulnerability

HIGH
Advisory Identifier: GHSA-4xjh-m3qx-49wc
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CVSS 7.5
CWE-59
Published
Advisory Summary

CVE-2018-17567 is a HIGH (CVSS 7.5) jekyll allows attackers to access vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting Jekyll libraries in the RubyGems ecosystem. The issue involves jekyll allows attackers to access arbitrary files by specifying a symlink. Remediation is available by upgrading affected packages to version 3.6.3, 3.7.4, 3.8.4.

CVE-2018-17567 at a Glance

CVE Identifier CVE-2018-17567
GHSA Identifier GHSA-4xjh-m3qx-49wc
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product Jekyll
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-2018-17567

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

jekyll fixed: 3.6.3 
Upgrade jekyll to 3.6.3
jekyll fixed: 3.7.4 
Upgrade jekyll to 3.7.4
jekyll fixed: 3.8.4 
Upgrade jekyll to 3.8.4
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 jekyll

How to Check if You Are Affected

To determine whether your application is affected by CVE-2018-17567, inspect your project dependencies for Jekyll:

inspect dependencies for jekyll

Analyze the terminal output to locate any version of Jekyll in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.6.3), 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-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. In Jekyll, 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

Jekyll through 3.6.2, 3.7.x through 3.7.3, and 3.8.x through 3.8.3 allows attackers to access arbitrary files by specifying a symlink in the `include` key in the `_config.yml` file.

CVE-2018-17567 Affected Jekyll Versions

3 component(s)
Fixed Versions:
3.6.33.7.43.8.4
Product / Package Ecosystem Affected Versions Fixed Version
jekyll
gem/jekyll
RubyGems
< 3.6.3
3.6.3
jekyll
gem/jekyll
RubyGems
≥ 3.7.0
< 3.7.4
3.7.4
jekyll
gem/jekyll
RubyGems
≥ 3.8.0
< 3.8.4
3.8.4

References

NVD — CVE-2018-17567 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-17567
Jekyll Source Repository REPOSITORY
https://github.com/jekyll/jekyll/pull/7224
Jekyll Source Repository REPOSITORY
https://github.com/jekyll/jekyll
Jekyll Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/jekyll/CVE-2018-17567.yml
Jekyll Security Information SECURITY
https://jekyllrb.com/news/2018/09/19/security-fixes-for-3-6-3-7-3-8
lists.apache.org/thread.html/71da391... WEB
https://lists.apache.org/thread.html/71da391f584b2fb301d2df0e491b279d87287e2fb4b11309f04ad984@%3Ccommits.accumulo.apache.org%3E

Frequently Asked Questions

What is CVE-2018-17567?
CVE-2018-17567 is a security vulnerability in Jekyll involving Jekyll allows attackers to access arbitrary files by specifying a symlink under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which Jekyll versions are affected?
Affected versions include releases prior to 3.6.3, 3.7.4, 3.8.4 across affected packages: jekyll.
What version fixes CVE-2018-17567?
Upgrading to 3.6.3, 3.7.4, 3.8.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is jekyll affected?
Yes, jekyll is affected in releases prior to 3.6.3, 3.7.4, 3.8.4. Upgrade your dependency to 3.6.3, 3.7.4, 3.8.4 or later.
What is the CVSS score of CVE-2018-17567?
CVE-2018-17567 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-2018-17567?
CVE-2018-17567 is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following') (The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.).
How can I check RubyGems dependencies for CVE-2018-17567?
Run the dependency tree command: 'inspect dependencies for jekyll'. 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-4xjh-m3qx-49wc",
  "modified" : "2023-09-05T21:41:33Z",
  "published" : "2018-09-28T19:29:07Z",
  "aliases" : [ "CVE-2018-17567" ],
  "summary" : "Jekyll allows attackers to access arbitrary files by specifying a symlink",
  "details" : "Jekyll through 3.6.2, 3.7.x through 3.7.3, and 3.8.x through 3.8.3 allows attackers to access arbitrary files by specifying a symlink in the `include` key in the `_config.yml` file.",
  "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" : "jekyll"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.6.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "jekyll"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.7.0"
      }, {
        "fixed" : "3.7.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "jekyll"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.8.0"
      }, {
        "fixed" : "3.8.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-17567"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jekyll/jekyll/pull/7224"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jekyll/jekyll"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/jekyll/CVE-2018-17567.yml"
  }, {
    "type" : "WEB",
    "url" : "https://jekyllrb.com/news/2018/09/19/security-fixes-for-3-6-3-7-3-8"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/71da391f584b2fb301d2df0e491b279d87287e2fb4b11309f04ad984@%3Ccommits.accumulo.apache.org%3E"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-59" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T20:59:43Z",
    "nvd_published_at" : null
  }
}