Resource exhaustion in Naturalintelligence Fast-Xml-Parser

CVE-2023-34104

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.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (65.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 65.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-34104: held from 0.011 to 0.011.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: -0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-34104?
CVE-2023-34104 is a high-severity vulnerability in Naturalintelligence Fast-Xml-Parser, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2023-06-06.
How severe is CVE-2023-34104?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2023-34104 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.