01 Record
CVE-2021-27736
FusionAuth fusionauth-samlv2 before 0.5.4 allows XXE attacks via a forged AuthnRequest or LogoutRequest because parseFromBytes uses javax.xml.parsers.DocumentBuilderFactory unsafely.
UnratedPUBLISHEDCNA: mitre
CNA base scoreUnratedNo CNA CVSS vector
02 Description
FusionAuth fusionauth-samlv2 before 0.5.4 allows XXE attacks via a forged AuthnRequest or LogoutRequest because parseFromBytes uses javax.xml.parsers.DocumentBuilderFactory unsafely.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 1.31% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 70.5% of scored records. A rank, not a probability.
- NVD base score
- 6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-04-22 13:14Z5 YR AGO
- Last updated
- 2024-08-03 21:26Z2 YR AGO
- Reserved
- 2021-02-25
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-611Improper Restriction of XML External Entity ReferenceBase
- Data version
- 5.1
- Document digest
- 6b99fcb3bee13c5e482d1b36a2a68ef60f3d47151b6fc1381c047918c57a379f
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comhttps://github.com/FusionAuth/fusionauth-samlv2/compare/0.5.3...0.5.4
- github.comhttps://github.com/FusionAuth/fusionauth-samlv2/commit/c66fb689d50010662f705d5b585c6388ce555dbd
- www.compass-security.comhttps://www.compass-security.com/fileadmin/Research/Advisories/2021-03_CSNC-2021-004_FusionAuth_SAML_Library_XML_External_Entity.txt