Nokogiri
CVE-2019-5477
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization OS command sanitization, avoid shell exec
MITRE ATT&CK
2 techniques across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could execute arbitrary operating system commands on the host by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
A command injection vulnerability in Nokogiri v1.10.3 and earlier allows commands to be executed in a subprocess via Ruby's Kernel.open method. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This OS Command Injection vulnerability could allow attackers to execute arbitrary operating system commands on the host.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Avoid passing user input to shell commands. Use language-specific APIs instead of shell execution. Apply strict input validation with allowlists.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in rubygems
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as OS Command Injection (CWE-78), which allows attackers to execute arbitrary operating system commands on the host. A command injection vulnerability in Nokogiri v1.10.3 and earlier allows commands to be executed in a subprocess via Ruby's Kernel.open method. Processes are vulnerable only if the undocumented method Nokogiri::CSS::Tokenizer#load_file is being called with unsafe user input as the filename. This vulnerability appears in code generated by the Rexical gem versions v1.0.6 and earlier. Rexical is used by Nokogiri to generate lexical scanner code for parsing CSS queries. The underlying vulnerability was addressed in Rexical v1.0.7 and Nokogiri upgraded to this version of Rexical in Nokogiri v1.10.4. Affected products include: Nokogiri, Canonical Ubuntu Linux, Debian Debian Linux.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
A command injection vulnerability in Nokogiri v1.10.3 and earlier allows commands to be executed in a subprocess via Ruby's Kernel.open method. Processes are vulnerable only if the undocumented method Nokogiri::CSS::Tokenizer#load_file is being called with unsafe user input as the filename. This vulnerability appears in code generated by the Rexical gem versions v1.0.6 and earlier. Rexical is used by Nokogiri to generate lexical scanner code for parsing CSS queries. The underlying vulnerability was addressed in Rexical v1.0.7 and Nokogiri upgraded to this version of Rexical in Nokogiri v1.10.4.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
OS command injection occurs when an application passes unsanitized user input directly into system shell commands.
Affected Products (CPE)NVD
Nokogiri is an open source XML and HTML library for Ruby. Rated high severity (CVSS 8.2), this vulnerability is remotely
Denial-of-service in Nokogiri before 1.19.3 stems from three distinct ReDoS vulnerabilities in the CSS selector tokenize
Out-of-bounds memory read in Nokogiri (CRuby) versions before 1.19.4 crashes the host Ruby process when application code
Nokogiri is an open source XML and HTML library for the Ruby programming language. Rated high severity (CVSS 7.5), this
Nokogiri is an open source XML and HTML library for Ruby. Rated high severity (CVSS 7.5), this vulnerability is remotely
Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. Rated high sever
Heap memory leaks in Nokogiri's XSLT transform method (versions before 1.19.3) enable gradual denial of service against
Unchecked return value in Nokogiri's CRuby extension (versions 1.5.1 through 1.19.0) causes the `canonicalize` method to
Out-of-bounds read in Nokogiri's `NodeSet#[]` method (all versions before 1.19.4) enables an attacker who can supply a l
Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. Rated medium sev
NONET network restriction bypass in Nokogiri's JRuby implementation permits external resource fetching during XML Schema
Use-after-free in Nokogiri's CRuby XInclude processing (versions prior to 1.19.4) can leave Ruby wrapper objects pointin
Exploit-DB