CVE-2017-14623 in ldap.v2
Summary
by MITRE
In the ldap.v2 (aka go-ldap) package through 2.5.0 for Go, an attacker may be able to login with an empty password. This issue affects an application using this package if these conditions are met: (1) it relies only on the return error of the Bind function call to determine whether a user is authorized (i.e., a nil return value is interpreted as successful authorization) and (2) it is used with an LDAP server allowing unauthenticated bind.
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Analysis
by VulDB Data Team • 12/29/2022
The vulnerability described in CVE-2017-14623 represents a critical authentication bypass flaw within the go-ldap package version 2.5.0 and earlier. This issue stems from improper handling of LDAP bind operations when an empty password is provided, creating a security loophole that allows unauthorized access to systems. The vulnerability specifically impacts applications that depend on the ldap.v2 package for LDAP authentication and utilize LDAP servers that permit unauthenticated bind operations. The flaw occurs because the package does not adequately validate the authentication outcome when an empty password is submitted, leading to a false positive authorization state.
The technical implementation of this vulnerability involves the Bind function within the go-ldap package failing to properly distinguish between successful authentication with an empty password versus legitimate authentication. When an LDAP server accepts unauthenticated bind operations, the package's error handling mechanism interprets the successful completion of an empty password bind as valid authorization. This behavior violates fundamental security principles and creates a pathway for attackers to bypass authentication mechanisms entirely. The vulnerability manifests when applications relying on this package assume that a nil return value from the Bind function indicates successful authentication, without implementing additional validation checks.
From an operational perspective, this vulnerability poses significant risks to organizations using LDAP-based authentication systems. Attackers can exploit this flaw to gain unauthorized access to resources by simply providing an empty password during the authentication process. The impact extends beyond simple credential theft, potentially enabling privilege escalation and lateral movement within network environments. Applications affected by this vulnerability include those implementing LDAP authentication for web applications, database access controls, and enterprise resource planning systems. The vulnerability is particularly concerning in environments where LDAP servers are configured to allow anonymous or unauthenticated binds, which is a common configuration in many enterprise networks.
Security mitigation strategies for this vulnerability include immediate upgrading of the go-ldap package to version 2.5.1 or later, where the issue has been resolved through proper error handling and validation. Organizations should implement additional authentication layers beyond simple LDAP bind operations, including multi-factor authentication and certificate-based authentication. Application developers must modify their code to explicitly validate authentication outcomes rather than relying solely on nil return values from the Bind function. The vulnerability aligns with CWE-287, which addresses improper authentication issues, and maps to ATT&CK technique T1078 for valid accounts and T1566 for phishing attacks, as it enables unauthorized access through compromised authentication mechanisms. Network administrators should review LDAP server configurations to disable unauthenticated bind operations and implement proper access controls to prevent exploitation of this vulnerability.