PT-2021-17618 · Oracle · Javax.Xml.Parsers.Documentbuilderfactory

Philipp Mao · Published 2021-04-22 · Updated 2021-04-27 · CVE-2021-27736

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions: FusionAuth fusionauth-samlv2 versions prior to 0.5.4

Description: The issue allows XXE attacks via a forged AuthnRequest or LogoutRequest because the parseFromBytes function uses javax.xml.parsers.DocumentBuilderFactory unsafely. This can be exploited by sending malicious requests to the affected system.

Recommendations: For FusionAuth fusionauth-samlv2 versions prior to 0.5.4, update to version 0.5.4 or later to resolve the issue. As a temporary workaround, consider restricting access to the parseFromBytes function until a patch is applied. Avoid using the javax.xml.parsers.DocumentBuilderFactory unsafely in the affected API endpoints until the issue is resolved.

Exploit

Fix

XXE

Weakness Enumeration

CWE-611

Related Identifiers

CVE-2021-27736

Affected Products

Javax.Xml.Parsers.Documentbuilderfactory

References · 6

• 🔥 https://compass-security.com/fileadmin/Research/Advisories/2021-03_CSNC-2021-004_FusionAuth_SAML_Library_XML_External_Entity.txt · Exploit
• https://github.com/FusionAuth/fusionauth-samlv2/commit/c66fb689d50010662f705d5b585c6388ce555dbd · Patch
• https://github.com/FusionAuth/fusionauth-samlv2/compare/0.5.3...0.5.4 · Patch
• https://osv.dev/vulnerability/CVE-2021-27736 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-27736 · Security Note
• https://t.me/cvenotify/13549 · Telegram Post