CVE-2021-31404

Timing side channel vulnerability in UIDL request handler in Vaadin 10, 11-14, and 15-18

LOW

2.5

CVSS Score

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

Updated: June 17, 2026 at 03:51 AM UTC

3 products affected across 1 vendorVaadinFlowFlow Server

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Severity

LOW2.5

Exploit prediction

EPSS 0.2%

Description

Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:flow-server versions 1.0.0 through 1.0.13 (Vaadin 10.0.0 through 10.0.16), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.4.6 (Vaadin 14.0.0 through 14.4.6), 3.0.0 prior to 5.0.0 (Vaadin 15 prior to 18), and 5.0.0 through 5.0.2 (Vaadin 18.0.0 through 18.0.5) allows attacker to guess a security token via timing attack.

Affected

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

Flow · Vaadinmaven

95%

1.0.0 ≤ v < 1.0.141.1.0 ≤ v < 2.0.02.0.0 ≤ v < 2.4.73.0.0 ≤ v < 5.0.05.0.0 ≤ v < 5.0.3

Affected range stops below 1.0.14, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.0.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.4.7, 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

Affected range stops below 5.0.3, so it looks safe — our inference, not a vendor statement

Vaadin · Vaadinmaven

95%

v ≥ 10.0.010.0.0 ≤ v < 10.0.1711.0.0 ≤ v < 14.0.014.0.0 ≤ v < 14.4.715.0.0 ≤ v < 17.0.018.0.0 ≤ v < 18.0.610.0.0

Affected range stops below 10.0.17, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.0.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.4.7, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.0.0, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.0.6, so it looks safe — our inference, not a vendor statement

Flow Server · Vaadin

60%

v ≥ 1.0.01.0.0

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/9875

x_refsource_MISCVendor Advisory

Source: [email protected]

https://vaadin.com/security/cve-2021-31404

CVSS

2.5LOW[email protected]

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

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-208CWE-203

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