CVE-2026-66987 in AION
Summary
by MITRE • 11/06/2026
HCL AION is affected by a vulnerability where the account lockout mechanism did not sufficiently restrict repeated failed login attempts, allowing an attacker to make a large number of password guesses against a user account. This may increase the risk of account compromise through brute-force attacks, potentially resulting in unintended behavior or security impact under certain conditions.
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Analysis
by VulDB Data Team • 11/06/2026
The vulnerability identified within HCL AION represents a critical deficiency in the implementation of authentication controls, specifically concerning the enforcement of account lockout policies. In secure systems, an effective account lockout mechanism is designed to mitigate brute-force attacks by temporarily disabling or significantly slowing down access attempts after a predefined threshold of failed login credentials is reached. However, in this instance, the underlying logic governing these restrictions fails to adequately restrict repeated unsuccessful authentication requests. This flaw allows external actors to bypass standard rate-limiting protections and continue submitting password guesses against targeted user accounts without triggering immediate account suspension or progressive delays that would typically deter such automated attacks.
From a technical perspective, this issue aligns with CWE-307, which describes Improper Restriction of Excessive Authentication Attempts. The absence of robust throttling mechanisms means that the application does not enforce sufficient constraints on the frequency or volume of login attempts originating from a single source or targeting a specific identity. This lack of control creates an environment where automated tools can rapidly cycle through common passwords or utilize dictionary-based attacks with minimal resistance. The system fails to implement necessary countermeasures such as exponential backoff, temporary account locking after multiple failures, or CAPTCHA challenges that are standard practices for securing web applications against credential stuffing and brute-force exploitation vectors.
The operational impact of this vulnerability is significant, primarily due to the increased probability of unauthorized access through brute-force methods. An attacker leveraging this weakness can systematically test large volumes of password combinations until a match is found, especially if users have selected weak or predictable passwords. Successful compromise in this context does not merely result in unauthorized viewing of data but may lead to full account takeover depending on the privileges associated with the compromised identity. This could facilitate further lateral movement within the network, access to sensitive intellectual property stored within HCL AION, and potential manipulation of application configurations or workflows that rely on trusted user identities for execution.
This vulnerability is also closely related to MITRE ATT&CK technique T1110, which covers Brute Force attacks. By failing to limit authentication attempts, the system inadvertently supports this adversarial tactic, allowing attackers to operate with higher success rates and lower detection probabilities during the initial access phase of an attack lifecycle. The potential for unintended behavior or security impact arises because compromised accounts may be used to execute malicious actions that appear legitimate from a session perspective, making forensic analysis more difficult and increasing the blast radius if lateral movement occurs before the breach is detected.
To mitigate this risk, immediate remediation efforts should focus on implementing strict account lockout policies that temporarily disable accounts after a small number of consecutive failed login attempts. Additionally, deploying multi-factor authentication adds a critical layer of defense by requiring secondary verification beyond just password knowledge, thereby neutralizing the value of stolen or guessed credentials. Rate limiting at both the application and network levels can also help detect and block anomalous traffic patterns associated with automated brute-force tools. Regular auditing of authentication logs for unusual activity spikes is recommended to ensure that any residual gaps in detection are identified promptly.