CVE-2023-3597VulnerabilityPublished 25 Apr 2024Updated 11 Nov 2025

CVE-2023-3597: keycloak · Improper Authentication

Affects keycloakSource CVE Database V5

Not known to be exploited · CVSS 5.0 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.0Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Mavenorg.keycloak/keycloak`pkg:maven/org.keycloak/keycloak`Other threats	Affected =0 =23.0.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Monitor Keycloak vendor communications closely for official patches addressing CVE-2023-3597 and apply them promptly upon release. 2. Until patches are available, review and harden authentication flows, particularly the step-up authentication logic, to detect and block anomalous second-factor registrations. 3. Implement enhanced logging and alerting on MFA enrollment and changes to detect suspicious activity early. 4. Conduct regular audits of user authentication methods and revoke any unrecognized or suspicious second-factor credentials. 5. Enforce strict access controls and credential hygiene to minimize the risk of initial password compromise. 6. Consider deploying additional compensating controls such as network segmentation and anomaly detection to limit the impact of potential unauthorized access. 7. Educate administrators and users about the risk and encourage prompt reporting of unusual authentication behavior. 8. Evaluate alternative or supplementary identity providers if immediate patching is not feasible.

Description

A flaw was found in Keycloak, where it does not correctly validate its client step-up authentication in org.keycloak.authentication. This flaw allows a remote user authenticated with a password to register a false second authentication factor along with an existing one and bypass authentication.

Impact

For European organizations, the impact of CVE-2023-3597 can be significant, particularly for those that depend on Keycloak for identity and access management in critical infrastructure, government services, finance, healthcare, and other regulated sectors. The ability to bypass MFA undermines one of the strongest layers of defense against unauthorized access, increasing the risk of account takeover, data breaches, and lateral movement within networks. Confidentiality could be compromised if attackers gain access to sensitive data, while integrity and availability could be affected if attackers manipulate or disrupt services. The medium severity rating reflects that exploitation requires an authenticated user but no additional user interaction, making insider threats or compromised credentials more dangerous. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are released. Organizations with stringent compliance requirements under GDPR and other European regulations must consider the potential legal and reputational consequences of such a breach.

Summary

CVE-2023-3597 is a vulnerability identified in Keycloak, an open-source identity and access management solution widely used for securing applications and services. The flaw lies in the improper validation of client step-up authentication within the org.keycloak.authentication module. Step-up authentication is a security mechanism that requires users to provide additional authentication factors under certain conditions. In this case, the vulnerability allows a remote attacker who is already authenticated with a password (low privilege) to register a fraudulent second-factor authentication method alongside an existing legitimate one. This bypasses the intended multi-factor authentication (MFA) protections, potentially allowing the attacker to circumvent enhanced authentication requirements. The vulnerability affects Keycloak versions from initial releases up to 23.0.0. The CVSS 3.1 score of 5.0 (medium severity) reflects that the attack vector is network-based (AV:N), requires low privileges (PR:L), no user interaction (UI:N), and impacts confidentiality, integrity, and availability to a limited degree (C:L/I:L/A:L). Although no known exploits are currently reported in the wild, the flaw represents a significant risk to environments relying on Keycloak for MFA enforcement. The improper validation could lead to unauthorized access escalation, undermining the security posture of protected applications and services. The vulnerability was reserved in July 2023 and published in April 2024, with no official patches linked yet, indicating the need for vigilance and proactive mitigation by administrators.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2025, 16:22 UTC

Technical details

References

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