CVE-2019-18409

Ruby_parser-legacy Incorrect Permission Assignment for Critical Resource

7.8 High

The ruby_parser-legacy (aka legacy) gem 1.0.0 for Ruby allows local privilege escalation because of world-writable files. For example, if the brakeman gem (which has a legacy dependency) 4.5.0 through 4.7.0 is used, a local user can insert malicious code into the ruby_parser-legacy-1.0.0/lib/ruby_parser/legacy/ruby_parser.rb file.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.33%Up 0.1 points since Apr 14, 2021

What each source reports

NVD Score used 7.8

Record: CVE-2019-18409
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 4.6 MediumAV:L/AC:L/Au:N/C:P/I:P/A:P
Weakness: CWE-732
Updated: 2026-11-02

CVE List No score

Record: CVE-2019-18409
Updated: 2026-11-02

EUVDEUVD-2019-0704 No score

Record: EUVD-2019-0704
Updated: 2026-11-03

GitHub AdvisoriesGHSA-hhwc-8g49-j8jx 7.8

Ruby_parser-legacy Incorrect Permission Assignment for Critical Resource

The ruby_parser-legacy (aka legacy) gem 1.0.0 for Ruby allows local privilege escalation because of world-writable files. For example, if the brakeman gem (which has a legacy dependency) 4.5.0 through 4.7.0 is used, a local user can insert malicious code into the ruby_parser-legacy-1.0.0/lib/ruby_parser/legacy/ruby_parser.rb file.

Record: GHSA-hhwc-8g49-j8jx
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-732
Updated: 2026-11-02

OSV 7.8

Record: CVE-2019-18409
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVGHSA-hhwc-8g49-j8jx 7.8

Ruby_parser-legacy Incorrect Permission Assignment for Critical Resource

The ruby_parser-legacy (aka legacy) gem 1.0.0 for Ruby allows local privilege escalation because of world-writable files. For example, if the brakeman gem (which has a legacy dependency) 4.5.0 through 4.7.0 is used, a local user can insert malicious code into the ruby_parser-legacy-1.0.0/lib/ruby_parser/legacy/ruby_parser.rb file.

Record: GHSA-hhwc-8g49-j8jx
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-732
Updated: 2026-11-02

Affected products

zenspider ruby parser-legacy

Affected packages

Affected packages
Package	Affected	Fixed
`ruby_parser-legacy` RubyGems	through 1.0.0	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2019-18409 is a high vulnerability (CVSS 7.8) in Zenspider Ruby Parser-legacy, published October 24, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 26th percentile. No source names a fixed version.