CVE-2026-114420 in Secure Email Gateway
Summary
by MITRE • 11/04/2026
SEPPmail Secure Email Gateway before 15.1.1 does not neutralize LDAP metacharacters in an unauthenticated account-selection input in its GINA web interface. A remote unauthenticated attacker can enumerate email addresses.
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified in SEPPmail Secure Email Gateway versions prior to release 15.1.1 represents a critical failure in the application's handling of user-supplied data within its Graphical Interface for Authentication, commonly referred to as GINA. This component is responsible for managing authentication workflows and account selection processes that are integral to the system's access control mechanisms. The core technical flaw lies in the insufficient sanitization of Lightweight Directory Access Protocol metacharacters when processing input fields designated for unauthenticated account selection. Specifically, the application fails to neutralize special characters such as asterisks or null bytes that hold specific meaning within LDAP query structures. By allowing these metacharacters to pass through validation routines and into backend directory queries without proper encoding or escaping, the system inadvertently exposes its internal logic to manipulation by external actors.
This lack of input sanitization directly facilitates an LDAP injection attack vector. When a remote attacker submits crafted input containing LDAP metacharacters, the application constructs database queries that behave differently than intended by the developers. Instead of performing a strict string match for a specific email address or username, the query may become wildcard-based or logically altered to return broader sets of results. This deviation allows an unauthenticated user to bypass standard authentication requirements and interact directly with the directory service backend through the web interface. The attacker can systematically vary their input to probe different parts of the directory structure, effectively turning a simple account selection feature into a powerful enumeration tool for sensitive organizational data.
The operational impact of this vulnerability is significant, primarily centering on information disclosure and reconnaissance. An unauthenticated remote attacker can exploit this flaw to enumerate valid email addresses associated with users within the organization's directory. This capability provides adversaries with valuable intelligence regarding the existence of specific accounts, which can be leveraged for subsequent social engineering attacks such as phishing or spear-phishing campaigns. Furthermore, knowing valid usernames allows attackers to focus brute-force password attacks on high-value targets rather than guessing randomly across a large user base. While the primary impact described is enumeration, this information gathering phase often serves as the precursor to more severe compromises, including unauthorized access and potential data exfiltration if other vulnerabilities are present in the authentication chain.
From a classification perspective, this vulnerability aligns with CWE-90, which describes Improper Neutralization of Special Elements used in an SQL Command, specifically adapted here for LDAP injection contexts often categorized under CWE-90 or more broadly as Injection flaws (CWE-78). In terms of the MITRE ATT&CK framework, this behavior corresponds to techniques related to Discovery and Credential Access. Specifically, it facilitates Account Enumeration via T1087, where attackers discover accounts on a system or network to narrow their attack scope. It also relates to LDAP Injection patterns that allow for unauthorized data retrieval from directory services. The vulnerability underscores the importance of treating all input fields as untrusted, even those appearing benign like account selection boxes in administrative interfaces.
To mitigate this risk, organizations running SEPPmail Secure Email Gateway versions earlier than 15.1.1 must apply the vendor-provided patch immediately to address the input validation deficiencies. Until an update is applied, administrators should consider implementing network-level controls such as web application firewalls that can detect and block LDAP injection payloads in HTTP requests targeting the GINA interface. Additionally, restricting access to the administrative interfaces by IP whitelist or multi-factor authentication can reduce the attack surface available to unauthenticated remote actors. It is also advisable to review logging mechanisms to ensure that anomalous query patterns resulting from enumeration attempts are captured for forensic analysis and alerting purposes.