CVE-2024-4629 is a vulnerability identified in Keycloak version 24.0.3, an open-source identity and access management solution widely used for authentication and authorization. The vulnerability stems from improper enforcement of a single, unique action related to brute force protection during login attempts. Specifically, the system's brute force protection mechanism is designed to lock out users after a configured number of failed login attempts to prevent password guessing attacks. However, this flaw allows attackers to circumvent these protections by exploiting the timing of login requests. By sending multiple login attempts simultaneously, attackers can bypass the intended sequential enforcement of the lockout threshold. This timing loophole means that the system counts these simultaneous attempts separately before the lockout is triggered, effectively allowing more password guesses than the configured limit. The vulnerability does not require any prior authentication or user interaction, and the attack can be launched remotely over the network. The impact includes potential compromise of user accounts due to increased password guessing opportunities, threatening confidentiality and integrity of user data. The CVSS v3.1 base score is 6.5, indicating medium severity, with attack vector as network, low attack complexity, no privileges required, no user interaction, and impact on confidentiality and integrity but not availability. No known exploits have been reported in the wild, and no official patches or mitigations have been linked at the time of disclosure. This vulnerability highlights a design weakness in the brute force protection logic, specifically in handling concurrent login attempts and enforcing unique action constraints.

The primary impact of CVE-2024-4629 is the increased risk of successful brute force attacks against user accounts managed by Keycloak 24.0.3. By bypassing the lockout mechanism, attackers can attempt more password guesses than intended, raising the likelihood of credential compromise. This can lead to unauthorized access to sensitive systems and data protected by Keycloak authentication, undermining confidentiality and integrity. Organizations relying on Keycloak for critical identity management, especially those with high-value or sensitive user accounts, face elevated risk of account takeover, data breaches, and potential lateral movement within their networks. While availability is not directly impacted, the breach of authentication controls can have cascading effects on overall security posture. The vulnerability affects any deployment of the affected Keycloak version exposed to untrusted networks, including cloud services, enterprise applications, and government systems. The lack of authentication or user interaction requirements lowers the barrier for exploitation, increasing the threat landscape. Although no active exploits are known, the medium severity score and the widespread use of Keycloak make timely mitigation important to prevent future attacks.

To mitigate CVE-2024-4629, organizations should first upgrade Keycloak to a version where this vulnerability is fixed once an official patch is released. In the absence of an immediate patch, administrators can implement several practical controls: 1) Deploy external rate limiting or web application firewalls (WAFs) to detect and block rapid, simultaneous login attempts from the same IP or user account. 2) Configure Keycloak to use additional multi-factor authentication (MFA) methods to reduce the risk of compromised credentials being abused. 3) Monitor authentication logs for unusual patterns of concurrent login attempts and implement alerting for brute force indicators. 4) Consider deploying network-level protections such as IP reputation filtering and geo-blocking to limit exposure. 5) If possible, adjust the brute force protection settings to be more aggressive or implement custom logic to handle concurrent attempts more effectively. 6) Educate users on strong password policies and encourage the use of password managers to reduce guessable credentials. 7) Isolate Keycloak instances behind VPNs or internal networks where feasible to reduce exposure to external attackers. These measures, combined with prompt patching, will reduce the risk of exploitation and protect account security.