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fast-xml-parser vulnerable to Regex Injection via Doctype Entities

High severity GitHub Reviewed Published Jun 6, 2023 in NaturalIntelligence/fast-xml-parser • Updated Jan 25, 2024

Package

npm fast-xml-parser (npm)

Affected versions

>= 4.1.3, < 4.2.4

Patched versions

4.2.4

Description

Impact

"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 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.

Patches

The problem has been resolved in v4.2.4

Workarounds

Avoid using DOCTYPE parsing by processEntities: false option.

References

@amitguptagwl amitguptagwl published to NaturalIntelligence/fast-xml-parser Jun 6, 2023
Published to the GitHub Advisory Database Jun 6, 2023
Reviewed Jun 6, 2023
Published by the National Vulnerability Database Jun 6, 2023
Last updated Jan 25, 2024

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.138%
(50th percentile)

Weaknesses

CVE ID

CVE-2023-34104

GHSA ID

GHSA-6w63-h3fj-q4vw

Source code

Credits

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