CVE-2023-34104

HIGH
Published Jun 6, 20233y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Jun 6, 2023 3y ago
Last Modified Jun 17, 2026 2w ago

Description

fast-xml-parser is an open source, pure javascript xml parser. fast-xml-parser allows special characters in entity names, which are not escaped or sanitized. Since the entity name is used for creating a regex for searching and replacing entities in the XML body, an attacker can abuse it for denial of service (DoS) attacks. By crafting an entity name that results in an intentionally bad performing regex and utilizing it in the entity replacement step of the parser, this can cause the parser to stall for an indefinite amount of time. This problem has been resolved in v4.2.4. Users are advised to upgrade. Users unable to upgrade should avoid using DOCTYPE parsing by setting the `processEntities: false` option.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-1333
CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 1

VendorProductVersionRange
naturalintelligencefast-xml-parser* <4.2.4

References 3

  • github.com https://github.com/NaturalIntelligence/fast-xml-parser/commit/39b0e050bb909e8499478657f84a3076e39ce76c
    Patch
  • github.com https://github.com/NaturalIntelligence/fast-xml-parser/commit/a4bdced80369892ee413bf08e28b78795a2b0d5b
  • github.com https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-6w63-h3fj-q4vw
    MitigationVendor Advisory

Remediation

  • github.com https://github.com/NaturalIntelligence/fast-xml-parser/commit/39b0e050bb909e8499478657f84a3076e39ce76c
    Patch