SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.5EPSS 1.14%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.14% probability · 65th percentile
CISA KEV
Not listed
Weakness
CWE-400, CWE-1333
Affected
naturalintelligence/fast-xml-parser
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.