CVE-2024-23565: HCL Aftermarket EPC DoS Vulnerability

CVE-2024-23565 Overview

CVE-2024-23565 affects HCL Aftermarket EPC, where the Forgot Password functionality lacks a rate limiting or mail throttling mechanism. An unauthenticated attacker can repeatedly trigger password reset emails to arbitrary recipients. Automated abuse can flood target inboxes and exhaust downstream mail relay resources. The weakness is classified under CWE-799: Improper Control of Interaction Frequency. The issue can be exercised by a human operator, a bot, or malware seeking to disrupt communications or degrade service availability.

Critical Impact
Unauthenticated network attackers can generate high-volume email traffic through the password reset endpoint, resulting in denial of service, mail server abuse, and potential manipulation of dependent program logic.

Affected Products

HCL Aftermarket EPC (Forgot Password functionality)

Discovery Timeline

2026-07-17 - CVE-2024-23565 published to NVD
2026-07-17 - Last updated in NVD database

Technical Details for CVE-2024-23565

Vulnerability Analysis

The vulnerability resides in the Forgot Password workflow of HCL Aftermarket EPC. The endpoint accepts password reset requests without enforcing per-user, per-IP, or per-session frequency controls. Each request generates an outbound email, so an attacker can submit thousands of requests in a short window.

Because authentication is not required to trigger the reset flow, exploitation only needs network access to the application. The absence of throttling means the application itself acts as an amplifier, converting small HTTP requests into a large volume of outbound SMTP traffic.

The impact extends beyond simple inbox flooding. Sustained abuse consumes mail queue capacity, may trigger blocklisting of the sending domain, and can obscure legitimate reset notifications. Where downstream logic depends on reset token issuance or audit events, the flood can also compromise program logic and monitoring signal quality.

Root Cause

The root cause is missing interaction-frequency enforcement on the password reset endpoint. The application does not implement rate limiting, CAPTCHA validation, exponential backoff, or per-account email dispatch quotas. This maps directly to CWE-799: Improper Control of Interaction Frequency.

Attack Vector

An attacker interacts with the public Forgot Password form or its underlying HTTP endpoint. They submit repeated requests containing a target email address or username. Each request causes the application to dispatch a password reset email. Automation through scripts or botnets scales the attack to thousands of messages per minute without authentication or user interaction.

No verified public proof-of-concept code is available for this issue. Refer to the HCL Software Knowledge Base Article for vendor-provided technical details.

Detection Methods for CVE-2024-23565

Indicators of Compromise

High volume of HTTP POST requests to the Forgot Password endpoint from a single source IP or narrow IP range within a short interval.
Spikes in outbound SMTP traffic from the HCL Aftermarket EPC host, particularly password reset messages to identical or sequential recipients.
Multiple password reset emails delivered to the same mailbox within minutes without corresponding legitimate user activity.
Mail server queue growth or bounce-back volume increase correlated with application traffic spikes.

Detection Strategies

Deploy web application firewall rules that count requests per source IP against the Forgot Password URL and alert on threshold breaches.
Correlate application access logs with mail relay logs to identify one-to-one request-to-email amplification patterns.
Baseline normal password reset request volume and alert on statistically significant deviations.

Monitoring Recommendations

Ingest HCL Aftermarket EPC web server and mail relay logs into a centralized SIEM for correlation and long-term retention.
Monitor for repeated requests to the reset endpoint targeting the same account, which indicates single-user harassment or credential-stuffing reconnaissance.
Track outbound email reputation metrics such as bounce rate and blocklist status to identify abuse in progress.

How to Mitigate CVE-2024-23565

Immediate Actions Required

Apply the fix documented in the HCL Software Knowledge Base Article as soon as the patched build is available in your environment.
Place the Forgot Password endpoint behind a reverse proxy or WAF that enforces per-IP and per-account rate limits.
Restrict administrative and diagnostic interfaces to trusted networks while remediation is in progress.

Patch Information

HCL has published remediation guidance in HCL Software Knowledge Base Article KB0132294. Administrators should consult the article for supported fixed versions and upgrade instructions specific to their HCL Aftermarket EPC deployment.

Workarounds

Add a CAPTCHA challenge or proof-of-work mechanism in front of the Forgot Password form to prevent automated submission.
Implement application-layer rate limiting keyed on source IP, user agent, and target account identifier.
Cap the number of password reset emails delivered per account per hour at the mail relay or transport layer.
Enable account-lockout notifications only after a debounce window to reduce email amplification.

bash

# Example nginx rate limit for the password reset endpoint
limit_req_zone $binary_remote_addr zone=pwreset:10m rate=5r/m;

server {
    location /forgot-password {
        limit_req zone=pwreset burst=5 nodelay;
        proxy_pass http://aftermarket_epc_backend;
    }
}