CVE-2019-4393 in AppScan
Summary
by MITRE
HCL AppScan Standard is vulnerable to excessive authorization attempts
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Analysis
by VulDB Data Team • 05/17/2024
HCL AppScan Standard version 9.0.2.0 and earlier contains a vulnerability that allows for excessive authorization attempts, creating potential security risks for applications under assessment. This vulnerability stems from insufficient rate limiting and authorization control mechanisms within the scanning tool itself, which can be exploited by malicious actors to perform unauthorized access attempts against target applications. The flaw manifests when the application scan process does not adequately restrict the number of authentication attempts or authorization requests that can be made within a given time frame, potentially enabling credential stuffing or brute force attacks against the scanned applications.
The technical implementation of this vulnerability involves the application scan engine's handling of authentication tokens and session management during automated testing processes. When AppScan Standard performs security assessments against web applications, it may attempt to authenticate using various credential combinations or exploit authorization bypass techniques. Without proper rate limiting controls, these authorization attempts can occur at an excessive frequency, potentially overwhelming the target application's authentication mechanisms. This behavior creates opportunities for attackers to leverage the scanning tool as a vector for unauthorized access attempts, particularly when the tool is configured to perform aggressive authentication testing or when it encounters applications with weak authentication controls.
The operational impact of this vulnerability extends beyond simple authorization bypass scenarios and can significantly affect the security posture of organizations relying on HCL AppScan Standard for application security testing. Attackers could potentially use the excessive authorization attempts to identify weak authentication mechanisms, discover valid user accounts through account enumeration, or exhaust authentication rate limits on target applications. The vulnerability becomes particularly concerning when the scanning tool is configured with aggressive testing parameters or when it is used in environments where it has elevated privileges to perform authentication testing against multiple applications. Organizations may experience false positives in their security monitoring systems due to the high volume of authorization attempts generated by the scanning process, potentially masking actual security incidents.
Mitigation strategies for this vulnerability should focus on implementing proper rate limiting controls within the AppScan Standard configuration, establishing clear boundaries for authentication attempts during scanning operations, and monitoring the scanning tool's behavior for unusual authorization patterns. Organizations should configure the scanning tool to limit the number of authentication attempts per minute or hour, implement time-based delays between authorization requests, and ensure that the scanning process does not overwhelm target applications' authentication systems. Additionally, security teams should regularly review the scanning tool's authorization attempt logs and implement monitoring controls to detect unusual patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-307, which addresses improper restriction of excessive authentication attempts, and can be mapped to ATT&CK technique T1110 for credential access through brute force or credential stuffing attacks. Organizations should also consider updating to HCL AppScan Standard version 9.0.2.1 or later, which includes fixes for this specific authorization attempt limitation issue.