HOMEVULNERABILITIESCVE-2019-5477
CRITICAL

CVE-2019-5477

CWE-78Published: August 16, 2019· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2019-5477 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Canonical1 product(s)
ubuntu linux
Debian1 product(s)
debian linux
nokogiri1 product(s)
nokogiri
Source: NVD CPE · 7 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/sparklemotion/nokogiri/issues/1915
PATCHhttps://github.com/sparklemotion/nokogiri/issues/1915
ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/09/msg00027.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00018.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00019.html
ADVISORYhttps://security.gentoo.org/glsa/202006-05
ADVISORYhttps://usn.ubuntu.com/4175-1/
ADVISORYhttps://lists.debian.org/debian-lts-announce/2019/09/msg00027.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00018.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00019.html
ADVISORYhttps://security.gentoo.org/glsa/202006-05
ADVISORYhttps://usn.ubuntu.com/4175-1/

All References (16)

→
https://github.com/sparklemotion/nokogiri/issues/1915Patch · Third Party Advisory
→
https://github.com/tenderlove/rexical/blob/master/CHANGELOG.rdocRelease Notes
→
https://hackerone.com/reports/650835Permissions Required
→
https://lists.debian.org/debian-lts-announce/2019/09/msg00027.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00018.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00019.htmlMailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202006-05Third Party Advisory
→
https://usn.ubuntu.com/4175-1/Third Party Advisory
→
https://github.com/sparklemotion/nokogiri/issues/1915Patch · Third Party Advisory
→
https://github.com/tenderlove/rexical/blob/master/CHANGELOG.rdocRelease Notes
→
https://hackerone.com/reports/650835Permissions Required
→
https://lists.debian.org/debian-lts-announce/2019/09/msg00027.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00018.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00019.htmlMailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202006-05Third Party Advisory

Quick Facts

CVE IDCVE-2019-5477
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-78
CISA KEVNo
Affected3 vendor(s)
PublishedAug 16, 2019

Related CVEs (CWE-78)

CVE-2021-35402
KEV10.0
CVE-2013-0804
10.0
CVE-2024-52034
10.0
CVE-2024-47407
10.0
CVE-2026-33478
KEV10.0
CVE-2012-4177
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2019-5477 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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