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.
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Fast-xml-parser | Fast-xml-parser_project | * | 4.2.4 (excluding) |
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.