#VU81287 Observable discrepancy in framework - CVE-2021-31403

Vulnerability identifier: #VU81287

Vulnerability risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-31403

CWE-ID: CWE-203

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
framework
Server applications / Frameworks for developing and running applications

Vendor: vaadin

Description

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to non-constant-time comparison of CSRF tokens in UIDL request handler. A local user can guess a security token for Fusion endpoints and then use this information to launch further attacks against the affected system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

framework: 7.0.0 - 8.12.2

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External links
https://vaadin.com/security/cve-2021-31403
https://github.com/vaadin/framework/pull/12188
https://github.com/vaadin/framework/pull/12190

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.