CVE-2021-31403

4.0 MEDIUM 0.3% exploit odds Fix listed

What it is

Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:vaadin-server versions 7.0.0 through 7.7.23 (Vaadin 7.0.0 through 7.7.23), and 8.0.0 through 8.12.2 (Vaadin 8.0.0 through 8.12.2) allows attacker to guess a security token via timing attack

At a glance

Exploitability: Can be exploited locally on the machine without logging in. Limited direct impact.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2021-04-23 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:51 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 4.0 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-04-23 16:15 UTC
Last modified: 2026-06-17 03:51 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-208
Record status: Modified

Affected

Vaadin < 7.7.24
Vaadin < 8.12.3

Attack profile CVSS 3.1 · 4.0

Attack vector: Local
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Raw vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-31403.md and follow it. Check whether this project is affected by CVE-2021-31403. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record