CVE-2019-10842: Bootstrap sass Bootstrap-sass Contains Code Execution Backdoor Vulnerability

CRITICAL
Advisory Identifier: GHSA-vqqv-v9m2-48p2
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CVSS 9.8
CWE-94
Published
Advisory Summary

CVE-2019-10842 is a CRITICAL (CVSS 9.8) bootstrap-sass contains code execution backdoor vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Bootstrap sass libraries in the RubyGems ecosystem. The issue involves bootstrap-sass contains code execution backdoor. Remediation is available by upgrading affected packages to version 3.2.0.4.

CVE-2019-10842 at a Glance

CVE Identifier CVE-2019-10842
GHSA Identifier GHSA-vqqv-v9m2-48p2
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Bootstrap sass
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/A:H).

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 High (I:H)
Availability High (A:H)

How to Fix CVE-2019-10842

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

bootstrap-sass fixed: 3.2.0.4 
Upgrade bootstrap-sass to 3.2.0.4
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 bootstrap-sass

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-10842, inspect your project dependencies for Bootstrap sass:

inspect dependencies for bootstrap-sass

Analyze the terminal output to locate any version of Bootstrap sass in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.2.0.4), 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-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Bootstrap sass, 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

Arbitrary code execution (via backdoor code) was discovered in bootstrap-sass 3.2.0.3, when downloaded from rubygems.org. An unauthenticated attacker can craft the ___cfduid cookie value with base64 arbitrary code to be executed via eval(), which can be leveraged to execute arbitrary code on the target system. Note that there are three underscore characters in the cookie name. This is unrelated to the __cfduid cookie that is legitimately used by Cloudflare.

CVE-2019-10842 Affected Bootstrap sass Versions

1 component(s)
Fixed Versions:
3.2.0.4
Product / Package Ecosystem Affected Versions Fixed Version
bootstrap-sass
gem/bootstrap-sass
RubyGems
≥ 3.2.0.3
< 3.2.0.4
All 1 versions
3.2.0.3
3.2.0.4

References

NVD — CVE-2019-10842 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-10842
Bootstrap sass Source Repository REPOSITORY
https://github.com/twbs/bootstrap-sass/issues/1195
Bootstrap sass Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/bootstrap-sass/CVE-2019-10842.yml
Bootstrap sass Source Repository REPOSITORY
https://github.com/twbs/bootstrap-sass
snyk.io/blog/malicious-remo... WEB
https://snyk.io/blog/malicious-remote-code-execution-backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem
snyk.io/vuln/snyk-ruby-boot... WEB
https://snyk.io/vuln/SNYK-RUBY-BOOTSTRAPSASS-174093

Frequently Asked Questions

What is CVE-2019-10842?
CVE-2019-10842 is a security vulnerability in Bootstrap sass involving Bootstrap-sass contains code execution backdoor under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Bootstrap sass versions are affected?
Affected versions include releases prior to 3.2.0.4 across affected packages: bootstrap-sass.
What version fixes CVE-2019-10842?
Upgrading to 3.2.0.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bootstrap-sass affected?
Yes, bootstrap-sass is affected in releases prior to 3.2.0.4. Upgrade your dependency to 3.2.0.4 or later.
What is the CVSS score of CVE-2019-10842?
CVE-2019-10842 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-10842?
CVE-2019-10842 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check RubyGems dependencies for CVE-2019-10842?
Run the dependency tree command: 'inspect dependencies for bootstrap-sass'. 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-vqqv-v9m2-48p2",
  "modified" : "2023-08-25T23:39:10Z",
  "published" : "2019-04-04T16:28:47Z",
  "aliases" : [ "CVE-2019-10842" ],
  "summary" : "Bootstrap-sass contains code execution backdoor",
  "details" : "Arbitrary code execution (via backdoor code) was discovered in bootstrap-sass 3.2.0.3, when downloaded from rubygems.org. An unauthenticated attacker can craft the ___cfduid cookie value with base64 arbitrary code to be executed via eval(), which can be leveraged to execute arbitrary code on the target system. Note that there are three underscore characters in the cookie name. This is unrelated to the __cfduid cookie that is legitimately used by Cloudflare.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "bootstrap-sass"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.2.0.3"
      }, {
        "fixed" : "3.2.0.4"
      } ]
    } ],
    "versions" : [ "3.2.0.3" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-10842"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/twbs/bootstrap-sass/issues/1195"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/bootstrap-sass/CVE-2019-10842.yml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/twbs/bootstrap-sass"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/blog/malicious-remote-code-execution-backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-RUBY-BOOTSTRAPSASS-174093"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:58:14Z",
    "nvd_published_at" : null
  }
}