CVE-2021-31406

low-risk
Published 2021-04-23

Non-constant-time comparison of CSRF tokens in endpoint request handler in com.vaadin:flow-server versions 3.0.0 through 5.0.3 (Vaadin 15.0.0 through 18.0.6), and com.vaadin:fusion-endpoint version 6.0.0 (Vaadin 19.0.0) allows attacker to guess a security token for Fusion endpoints via timing attack.

Do I need to act?

-
0.05% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.0/10 Medium
LOCAL / HIGH complexity

Affected Products (4)

Flow
Flow

Affected Vendors

Vaadin

References (4)

Patch https://github.com/vaadin/flow/pull/10157
Vendor Advisory https://vaadin.com/security/cve-2021-31406
Patch https://github.com/vaadin/flow/pull/10157
Vendor Advisory https://vaadin.com/security/cve-2021-31406
20
/ 100
low-risk
Severity 10/34 · Low
Exploitability 0/34 · Minimal
Exposure 10/34 · Low