CVE-2024-39398: Adobe Commerce Auth Bypass Vulnerability

CVE-2024-39398 Overview

CVE-2024-39398 is an Improper Restriction of Excessive Authentication Attempts vulnerability [CWE-307] affecting Adobe Commerce and Magento Open Source. Adobe Commerce versions 2.4.7-p1, 2.4.6-p6, 2.4.5-p8, 2.4.4-p9 and earlier fail to limit repeated authentication attempts. Attackers can exploit this weakness to perform brute force attacks against authentication endpoints. Successful exploitation results in a security feature bypass and potentially unauthorized account access. Exploitation does not require user interaction, although attack complexity is rated high.

Critical Impact
Network-based attackers can brute force credentials against affected Adobe Commerce deployments, leading to account takeover and unauthorized access to merchant and customer data.

Affected Products

Adobe Commerce 2.4.4 through 2.4.4-p9
Adobe Commerce 2.4.5 through 2.4.5-p8, 2.4.6 through 2.4.6-p6, and 2.4.7 through 2.4.7-p1
Magento Open Source (equivalent version ranges)

Discovery Timeline

2024-08-14 - CVE-2024-39398 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-39398

Vulnerability Analysis

The vulnerability stems from missing rate limiting and lockout enforcement on authentication endpoints in Adobe Commerce. Without controls on repeated failed logins, an attacker can submit large volumes of credential pairs without triggering account lockouts or throttling. This permits credential stuffing using leaked password lists and traditional dictionary attacks against customer and administrative accounts.

The weakness maps to [CWE-307: Improper Restriction of Excessive Authentication Attempts]. Successful authentication grants the attacker the privileges of the targeted account, with high impact to both confidentiality and integrity of stored data. Availability is not impacted by this specific flaw.

Root Cause

The root cause is the absence or insufficiency of enforcement logic that should track failed authentication attempts and impose lockouts, delays, or CAPTCHA challenges. The application accepts repeated login submissions from the same source or against the same account without throttling, leaving authentication endpoints exposed to automated brute force tooling.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker scripts authentication requests against the Adobe Commerce login interface and iterates through username and password combinations. Because attack complexity is high, conditions such as predictable usernames, weak password policies, or pre-existing credential leaks are likely required for successful exploitation. No public proof-of-concept exploit is currently available, and the CVE is not listed in the CISA Known Exploited Vulnerabilities catalog.

Technical details and patch information are available in the Adobe Magento Security Advisory APSB24-61.

Detection Methods for CVE-2024-39398

Indicators of Compromise

High volumes of HTTP POST requests to /customer/account/loginPost/ or /admin login endpoints from a single source or distributed botnet.
Repeated authentication failures followed by a successful login for the same account within a short time window.
Unusual geolocation or user-agent diversity in authentication logs targeting customer or administrative accounts.

Detection Strategies

Aggregate web server and application logs to identify spikes in failed login responses per source IP, per account, and per session.
Correlate authentication failure ratios against baseline traffic to flag credential stuffing campaigns.
Apply detection rules on web application firewalls (WAFs) to identify enumeration patterns and known credential-stuffing user agents.

Monitoring Recommendations

Forward Adobe Commerce access and authentication logs to a centralized SIEM for correlation and alerting on brute force patterns.
Track newly successful logins that follow long sequences of failed attempts and trigger automated response workflows.
Monitor for post-authentication anomalies such as bulk order exports, admin role changes, or new payment integrations.

How to Mitigate CVE-2024-39398

Immediate Actions Required

Upgrade Adobe Commerce and Magento Open Source to the fixed releases published in Adobe Security Bulletin APSB24-61.
Enforce multi-factor authentication (MFA) on all administrative accounts and recommend MFA for customer accounts.
Reset credentials for any account showing successful logins preceded by repeated failures.

Patch Information

Adobe addressed CVE-2024-39398 in the security update referenced in advisory APSB24-61. Administrators should apply the latest patch level for their major version branch (2.4.7, 2.4.6, 2.4.5, or 2.4.4) and verify the upgrade against the post-installation version check in the Adobe Commerce admin console.

Workarounds

Configure a WAF or reverse proxy to rate-limit requests to loginPost and admin authentication endpoints.
Enable CAPTCHA on storefront and admin login forms via the Adobe Commerce security configuration.
Restrict access to the admin login URL by IP allowlist where operationally feasible.

bash

# Example: nginx rate limit for Adobe Commerce login endpoints
limit_req_zone $binary_remote_addr zone=login_zone:10m rate=5r/m;

location ~* /(customer/account/loginPost|admin)/ {
    limit_req zone=login_zone burst=5 nodelay;
    proxy_pass http://magento_backend;
}