What is the CVSS score of CVE-2021-27736?

CVE-2021-27736 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N. EPSS exploitation probability: 1.3%.

Is there a public PoC exploit available for CVE-2021-27736?

Yes, a public proof-of-concept exploit is available for CVE-2021-27736. Prioritise patching immediately. EPSS: 1.3%.

Is there a patch available for CVE-2021-27736?

Yes, a patch is available for CVE-2021-27736. Update the affected software to the latest version immediately.

Fusionauth CVE-2021-27736

MEDIUM

Improper Restriction of XML External Entity Reference (CWE-611)

2021-04-22 cve@mitre.org

XXE Fusionauth Saml V2

6.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

6.5 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

CVE Published

Apr 22, 2021 - 14:15 nvd

MEDIUM 6.5

DescriptionNVD

FusionAuth fusionauth-samlv2 before 0.5.4 allows XXE attacks via a forged AuthnRequest or LogoutRequest because parseFromBytes uses javax.xml.parsers.DocumentBuilderFactory unsafely.

AnalysisAI

FusionAuth fusionauth-samlv2 before 0.5.4 allows XXE attacks via a forged AuthnRequest or LogoutRequest because parseFromBytes uses javax.xml.parsers.DocumentBuilderFactory unsafely. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as XML External Entity (XXE) (CWE-611), which allows attackers to read arbitrary files or perform SSRF through XML processing. FusionAuth fusionauth-samlv2 before 0.5.4 allows XXE attacks via a forged AuthnRequest or LogoutRequest because parseFromBytes uses javax.xml.parsers.DocumentBuilderFactory unsafely. Affected products include: Fusionauth Saml V2. Version information: before 0.5.4.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Disable external entity processing in XML parsers, use JSON instead of XML where possible.