CVE-2019-8321: Rubygems update RubyGems Escape Sequence Injection Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-fr32-gr5c-xq5c
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CVSS 7.5
CWE-88
Published
Advisory Summary

CVE-2019-8321 is a HIGH (CVSS 7.5) rubygems escape sequence injection vulnerability vulnerability (CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')) affecting Rubygems update libraries in the RubyGems ecosystem. The issue involves rubygems escape sequence injection vulnerability in verbose. Remediation is available by upgrading affected packages to version 2.7.9, 3.0.2.

CVE-2019-8321 at a Glance

CVE Identifier CVE-2019-8321
GHSA Identifier GHSA-fr32-gr5c-xq5c
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Affected Product Rubygems update
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2019-8321

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

rubygems-update fixed: 2.7.9 
Upgrade rubygems-update to 2.7.9
rubygems-update fixed: 3.0.2 
Upgrade rubygems-update to 3.0.2
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 rubygems-update

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-8321, inspect your project dependencies for Rubygems update:

inspect dependencies for rubygems-update

Analyze the terminal output to locate any version of Rubygems update in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.7.9), 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-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'), where the product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. In Rubygems update, 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 RubyGems 2.6 and later through 3.0.2. Since Gem::UserInteraction#verbose calls say without escaping, escape sequence injection is possible.

CVE-2019-8321 Affected Rubygems update Versions

2 component(s)
Fixed Versions:
2.7.93.0.2
Product / Package Ecosystem Affected Versions Fixed Version
rubygems-update
gem/rubygems-update
RubyGems
≥ 2.6.0
< 2.7.9
2.7.9
rubygems-update
gem/rubygems-update
RubyGems
≥ 3.0.0
< 3.0.2
3.0.2

References

NVD — CVE-2019-8321 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-8321
Rubygems update Security Information SECURITY
https://blog.rubygems.org/2019/03/05/security-advisories-2019-03.html
Rubygems update Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubygems-update/CVE-2019-8321.yml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2020/08/msg00027.html
Rubygems update Security Information SECURITY
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html

Frequently Asked Questions

What is CVE-2019-8321?
CVE-2019-8321 is a security vulnerability in Rubygems update involving RubyGems Escape sequence injection vulnerability in verbose under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection').
Which Rubygems update versions are affected?
Affected versions include releases prior to 2.7.9, 3.0.2 across affected packages: rubygems-update.
What version fixes CVE-2019-8321?
Upgrading to 2.7.9, 3.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is rubygems-update affected?
Yes, rubygems-update is affected in releases prior to 2.7.9, 3.0.2. Upgrade your dependency to 2.7.9, 3.0.2 or later.
What is the CVSS score of CVE-2019-8321?
CVE-2019-8321 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2019-8321?
CVE-2019-8321 is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') (The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.).
How can I check RubyGems dependencies for CVE-2019-8321?
Run the dependency tree command: 'inspect dependencies for rubygems-update'. 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-fr32-gr5c-xq5c",
  "modified" : "2023-08-28T13:19:04Z",
  "published" : "2019-06-20T16:06:04Z",
  "aliases" : [ "CVE-2019-8321" ],
  "summary" : "RubyGems Escape sequence injection vulnerability in verbose",
  "details" : "An issue was discovered in RubyGems 2.6 and later through 3.0.2. Since Gem::UserInteraction#verbose calls say without escaping, escape sequence injection is possible.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "rubygems-update"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.6.0"
      }, {
        "fixed" : "2.7.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "rubygems-update"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.0.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-8321"
  }, {
    "type" : "WEB",
    "url" : "https://blog.rubygems.org/2019/03/05/security-advisories-2019-03.html"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubygems-update/CVE-2019-8321.yml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2020/08/msg00027.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-88" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2019-06-20T16:00:39Z",
    "nvd_published_at" : null
  }
}