CVE-2026-113438 in Pleasanter
Summary
by MITRE • 10/26/2026
Pleasanter provided fails to properly verify passwords in LDAP authentication when processing specially crafted requests under certain configurations. If exploited, an attacker may bypass LDAP authentication by providing only a valid Login ID, without a password. As a result, an attacker may view, alter or delete information stored in the product with the privilege of the account used to log in.
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Analysis
by VulDB Data Team • 10/26/2026
The vulnerability described involves a critical failure in the authentication logic within Pleasanter's Lightweight Directory Access Protocol integration mechanism. Under specific configuration scenarios, the application fails to enforce mandatory password verification when processing LDAP bind requests. This flaw represents a fundamental breakdown in the principle of multi-factor or dual-credential validation required for secure identity management systems. Instead of requiring both a valid user identifier and a corresponding secret credential, the system accepts authentication attempts based solely on the presence of a recognized Login ID. This behavior deviates from standard security protocols which dictate that access control decisions must be predicated on complete and verified credentials to ensure non-repudiation and integrity of identity assertions.
From a technical perspective, this issue aligns with CWE-287 Improper Authentication, specifically where the system fails to verify one or more required authentication factors. The root cause likely stems from conditional logic errors in the LDAP binding process, possibly due to misconfigured fallback mechanisms or incomplete implementation of RFC 4513 standards for Simple Authentication and Security Layer interactions. When an attacker submits a request containing only a valid username without any password data, the backend service incorrectly interprets this as a successful authentication event. This allows the creation of a session token associated with that user account despite the absence of proof of identity through a shared secret or cryptographic challenge-response mechanism.
The operational impact of this vulnerability is severe and directly compromises the confidentiality, integrity, and availability of data managed by Pleasanter. An attacker who exploits this flaw can gain unauthorized access to any account whose Login ID exists within the LDAP directory structure without needing prior knowledge of passwords. This effectively nullifies password-based security controls for all users integrated with the affected system. Once authenticated, the adversary inherits the privileges associated with that specific user role. Depending on the permissions assigned to the targeted account, this could range from viewing sensitive personal information and project details to altering critical configurations or deleting essential records. Such unauthorized actions undermine trust in the application's data integrity and can lead to significant business disruption or regulatory non-compliance depending on the nature of the stored data.
This exploitation pattern maps directly to MITRE ATT&CK technique T1078 Valid Accounts, where adversaries use legitimate credentials obtained through various means to maintain persistent access. In this specific case, however, no actual credential theft is required for the password component, making it a more straightforward initial access vector compared to traditional brute-force or phishing attacks. The attacker simply needs knowledge of valid usernames within the organization's directory service, which are often easily discoverable through public directories, social engineering, or previous data breaches. This lowers the barrier to entry significantly and increases the likelihood of successful exploitation by opportunistic threat actors scanning for weak authentication implementations across internet-facing services.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary corrective action is to apply vendor-provided patches that enforce strict password validation during LDAP bind operations regardless of configuration settings. Administrators should verify that their current configurations do not enable any legacy modes or simplified binding methods that bypass standard authentication flows until the patch is applied. Additionally, implementing multi-factor authentication at the application layer can provide a compensating control even if the underlying LDAP integration remains vulnerable in certain edge cases. Security teams should also audit user accounts for unusual login activity and ensure that least-privilege principles are strictly enforced to limit the potential damage of any single compromised account. Regular penetration testing focused on authentication bypass scenarios is recommended to validate the effectiveness of these controls over time.