CVE-2023-34104: naturalintelligence fast-xml-parser Uncontrolled Resource Consumption

Vulnerability summary

CVE-2023-34104 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in naturalintelligence fast-xml-parser. EPSS estimates a 1.13% chance of exploitation in the next 30 days, higher than 65.7% of scored vulnerabilities.

Timeline

1. 06-06-2023
   PublishedVulnerability first disclosed.
2. 02-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
• CWE-1333Inefficient Regular Expression ComplexityThe product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.