CVE-2026-78579 in Access Gateway
Summary
by MITRE • 09/08/2026
The Okta Access Gateway does not sanitize SAML assertion attribute values before interpolating them into LDAP search filters in the LDAP datastore configuration. The raw values are substituted directly into the filter string and passed to the LDAP search operation, resulting in modification of the intended query logic.
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Analysis
by VulDB Data Team • 09/08/2026
This vulnerability represents a critical injection flaw within the Okta Access Gateway architecture, specifically affecting the integration between SAML-based authentication assertions and backend Lightweight Directory Access Protocol (LDAP) directories. The core technical deficiency lies in the application's failure to perform adequate input sanitization or validation on attribute values extracted from incoming SAML assertions before these values are embedded into LDAP search filter strings. In a standard secure implementation, any user-supplied data that is incorporated into a query language must be strictly validated against an allowlist of expected characters and formats, or properly escaped to neutralize special syntax. However, in this scenario, the raw attribute values from the SAML token are interpolated directly into the LDAP filter without such protective measures. This lack of sanitization allows an attacker who controls the content of a SAML assertion to inject arbitrary LDAP query logic into the search operation.
The operational impact of this flaw is severe because it fundamentally alters the intended behavior of the authentication and authorization process. By manipulating the attribute values, an adversary can modify the structure of the LDAP search filter sent to the directory server. This capability enables several malicious outcomes, including unauthorized access through authentication bypasses where the attacker crafts a filter that always evaluates to true or matches privileged accounts regardless of credentials. Furthermore, it opens the door to sensitive data exfiltration via blind LDAP injection techniques, allowing an attacker to infer information about the directory structure and user attributes based on response times or error messages. The vulnerability effectively undermines the integrity of the identity provider's trust boundary, as the gateway blindly trusts the assertion content without verifying its safety for downstream query execution.
From a classification perspective, this issue aligns with CWE-90, which defines SQL Injection vulnerabilities but is broadly applicable to any injection flaw where untrusted data interferes with an interpreter's syntax. In the context of LDAP specifically, it maps directly to CWE-90: Improper Neutralization of Special Elements used in an SQL Command (LDAP Injection). Additionally, this vulnerability facilitates lateral movement and privilege escalation within the identity infrastructure, which corresponds to ATT&CK technique T1548.003, Abuse Elevation Control Mechanism, specifically through LDAP injection for authentication bypass or data access. The flaw exploits a fundamental principle of secure coding by failing to separate code (the query logic) from data (the user attributes), thereby allowing the latter to dictate the former.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary fix involves implementing strict input validation for all SAML attribute values before they are used in LDAP queries. This should include whitelisting allowed characters, enforcing length limits, and escaping special LDAP metacharacters such as asterisks, parentheses, null bytes, and backslashes. Alternatively, the system should utilize parameterized queries or safe API calls provided by the underlying LDAP library to ensure that user input is treated strictly as data rather than executable code. For organizations unable to immediately patch this vulnerability, network-level controls can be employed to restrict outbound traffic from the Access Gateway to only necessary LDAP ports and implement strict firewall rules to limit exposure. Regular security audits of identity provider configurations and continuous monitoring for anomalous authentication patterns are also recommended to detect potential exploitation attempts in real-time.