CVE-2020-36321

Directory traversal in development mode handler in Vaadin 14 and 15-17

HIGH

7.5

CVSS Score

Published: April 23, 2021 at 04:05 PM UTC

Updated: June 17, 2026 at 03:15 AM UTC

3 products affected across 1 vendorVaadinFlowFlow Server

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Severity

HIGH7.5

Exploit prediction

EPSS 1%

Description

Improper URL validation in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.4.1 (Vaadin 14.0.0 through 14.4.2), and 3.0 prior to 5.0 (Vaadin 15 prior to 18) allows attacker to request arbitrary files stored outside of intended frontend resources folder.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Flow · Vaadinmaven

95%

2.0.0 ≤ v < 2.4.23.0.0 ≤ v < 5.0.0

Affected range stops below 2.4.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 5.0.0, so it looks safe — our inference, not a vendor statement

Vaadin · Vaadinmaven

95%

v ≥ 14.0.014.0.0 ≤ v < 14.4.315.0.0 ≤ v < 18.0.014.0.0

Affected range stops below 14.4.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.0.0, so it looks safe — our inference, not a vendor statement

Flow Server · Vaadin

60%

v ≥ 2.0.02.0.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

x_refsource_MISCPatchThird Party Advisory

Source: [email protected]

https://github.com/vaadin/flow/pull/9392

x_refsource_MISCVendor Advisory

Source: [email protected]

https://vaadin.com/security/cve-2020-36321

CVSS

7.5HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-22

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