#VU88797 Session Fixation in Keycloak - CVE-2023-6787

Vulnerability identifier: #VU88797

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-6787

CWE-ID: CWE-384

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Keycloak
Server applications / Directory software, identity management

Vendor: Keycloak

Description

The vulnerability allows a remote attacker to hijack session of another user.

The vulnerability exists due to an error in the re-authentication mechanism in org.keycloak.authentication. An active keycloak session can be hijacked by initiating a new authentication (having the query parameter prompt=login) and forcing the user to enter his credentials once again. If the user cancels this re-authentication by clicking Restart login, the account takeover could take place as the new session, with a different SUB, will have the same SID as the previous session.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Keycloak: 22.0.0 - 24.0.2

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External links
https://github.com/keycloak/keycloak/security/advisories/GHSA-c9h6-v78w-52wj
https://access.redhat.com/errata/RHSA-2024:1867
https://access.redhat.com/errata/RHSA-2024:1868

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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