CVE-2026-107638 in pH7Builder
Summary
by MITRE • 10/08/2026
pH7Builder (pH7 Social Dating CMS) before 18.5.0 contains an improper restriction of authentication attempts vulnerability that allows attackers to bypass two-factor authentication by guessing TOTP codes without limits. Attackers who know an account password can submit unlimited 6-digit verification codes to VerificationCodeFormProcess.php to take over member, affiliate, or administrator accounts.
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Analysis
by VulDB Data Team • 10/08/2026
The identified vulnerability in pH7Builder prior to version 18.5.0 represents a critical failure in the implementation of multi-factor authentication controls, specifically within the time-based one-time password mechanism. This flaw is classified under CWE-307, which denotes Improper Restriction of Excessive Authentication Attempts. The core technical issue lies in the server-side logic handling the VerificationCodeFormProcess.php endpoint, where there are no rate-limiting mechanisms or account lockout policies applied to the verification code submission process. Consequently, an attacker who has already obtained a valid user password through phishing, credential stuffing, or other means can proceed directly to the second factor of authentication without facing any resistance from the system's security controls.
In a properly secured implementation, two-factor authentication systems must enforce strict limits on the number of incorrect attempts allowed within a specific time window to prevent brute-force attacks against short-lived codes such as six-digit TOTP values. The absence of these restrictions in pH7Builder allows an adversary to automate the submission of all possible one-time passcode combinations until a valid code is found. Given that standard TOTP implementations typically use a six-digit numeric format, there are only ten thousand potential permutations for any given time step. Without rate limiting or exponential backoff strategies, this search space can be exhausted in seconds using automated scripts, effectively rendering the second factor of authentication obsolete and reducing it to a mere formality rather than a genuine security barrier.
The operational impact of this vulnerability is severe, as it leads directly to complete account takeover for any user type within the platform, including regular members, affiliates, and administrators. For standard users, this compromise can lead to unauthorized access to personal data, private communications, or financial information if stored on the profile. However, the risk escalates significantly when administrator accounts are targeted. An attacker gaining administrative privileges through this method could potentially manipulate site configurations, inject malicious code into templates or plugins, exfiltrate database contents containing sensitive user credentials and payment details, or establish persistent backdoors within the content management system infrastructure. This undermines the fundamental trust model of the social dating platform and exposes both the organization and its users to significant data breach liabilities.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK technique T1110.003, which describes Brute Force: Password Guessing for Authentication Bypass. Although traditional brute force targets passwords, in this context it applies to the authentication factor itself due to the lack of restriction on attempts. To mitigate this issue, system administrators must ensure they are running pH7Builder version 18.5.0 or later where these restrictions have been implemented by the developers. For environments that cannot immediately upgrade, temporary mitigations include implementing a web application firewall rule to limit request rates for the VerificationCodeFormProcess.php endpoint based on source IP address and user session identifiers. Additionally, introducing CAPTCHA challenges after a small number of failed attempts can disrupt automated scripting tools without significantly impacting legitimate users. Long-term remediation should also involve reviewing all authentication flows across the platform to ensure consistent application of rate-limiting policies for every step in the login process.