CVE-2023-34104
fast-xml-parser vulnerable to Regex Injection via Doctype Entities
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.
How to fix CVE-2023-34104
To remediate CVE-2023-34104, upgrade the affected package to a fixed version below.
- —upgrade to 4.2.4 or later
Is CVE-2023-34104 being exploited?
Low — EPSS is 0.6%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 4.1.3, < 4.2.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |