CVE-2010-2940 in SSSD
Summary
by MITRE
The auth_send function in providers/ldap/ldap_auth.c in System Security Services Daemon (SSSD) 1.3.0, when LDAP authentication and anonymous bind are enabled, allows remote attackers to bypass the authentication requirements of pam_authenticate via an empty password.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 09/24/2021
The vulnerability identified as CVE-2010-2940 resides within the System Security Services Daemon (SSSD) version 1.3.0, specifically in the ldap_auth.c file where the auth_send function operates. This flaw represents a critical authentication bypass vulnerability that undermines the security posture of systems relying on SSSD for identity management and authentication services. The vulnerability manifests when the LDAP authentication mechanism is configured with anonymous bind enabled, creating a dangerous condition where remote attackers can exploit the system's authentication flow without providing valid credentials.
The technical flaw stems from improper validation within the auth_send function that fails to adequately verify authentication parameters when anonymous LDAP binding is permitted. When an empty password is submitted through the pam_authenticate interface, the system incorrectly processes this input as a valid authentication attempt rather than rejecting it as an invalid credential. This behavior violates fundamental security principles and creates a pathway for unauthorized access where legitimate authentication mechanisms are circumvented. The vulnerability operates at the intersection of LDAP protocol handling and PAM (Pluggable Authentication Modules) integration, where the authentication flow does not properly enforce credential requirements even when anonymous binding is enabled.
The operational impact of this vulnerability is severe and far-reaching for organizations utilizing SSSD 1.3.0 with LDAP authentication. Remote attackers can exploit this weakness to gain unauthorized access to systems and services that depend on SSSD for user authentication, potentially leading to complete compromise of the authentication infrastructure. The vulnerability affects systems where administrators have enabled anonymous bind for LDAP operations, which is often done for performance reasons or to support specific service requirements. However, this configuration becomes a security risk when combined with the authentication bypass flaw, creating an attack surface that allows malicious actors to authenticate without legitimate credentials. The vulnerability also impacts compliance with security frameworks that require strong authentication controls and proper credential validation.
Organizations should immediately implement mitigations that include disabling anonymous bind when LDAP authentication is in use, as this configuration is the primary vector for exploitation. The recommended approach involves reviewing and modifying LDAP server configurations to enforce authenticated binding for all operations. System administrators should also consider upgrading to SSSD versions that have patched this vulnerability, as newer releases contain proper input validation and authentication flow controls. Security monitoring should be enhanced to detect anomalous authentication patterns that might indicate exploitation attempts. Additionally, implementing network segmentation and access controls can help limit the potential impact of successful exploitation. This vulnerability aligns with CWE-287 which addresses improper authentication issues, and represents a significant concern from the ATT&CK framework perspective under the credential access category where adversaries attempt to bypass authentication mechanisms to gain system access. Organizations should also conduct comprehensive security assessments to identify all systems running vulnerable SSSD versions and ensure proper configuration management practices are implemented to prevent similar issues in the future.