CVE-2020-17477 : Vulnerability Insights and Analysis

CVE-2020-17477 is a vulnerability in UCS@school that allows unauthorized access to LDAP password hashes, potentially leading to elevated privileges.

Understanding CVE-2020-17477

What is CVE-2020-17477?

The vulnerability arises from incorrect LDAP ACLs in ucs-school-ldap-acls-master in UCS@school before version 4.4v5-errata. It enables remote teachers, staff, and school administrators to retrieve LDAP password hashes through LDAP search requests, such as sambaNTPassword, krb5Key, sambaPasswordHistory, and pwhistory.

The Impact of CVE-2020-17477

This vulnerability can result in unauthorized access to sensitive information, potentially allowing a teacher to escalate their privileges to that of an administrator using an NTLM hash.

Technical Details of CVE-2020-17477

Vulnerability Description

The issue stems from the improper configuration of LDAP ACLs, which permits the retrieval of critical password hashes.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions before UCS@school 4.4v5-errata are affected.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending LDAP search requests to retrieve password hashes, leading to unauthorized access.

Mitigation and Prevention

Immediate Steps to Take

Upgrade UCS@school to version 4.4v5-errata or later to mitigate the vulnerability.
Monitor LDAP access and review ACL configurations to ensure proper restrictions.

Long-Term Security Practices

Implement least privilege access controls to limit users' access to sensitive information.
Regularly review and update LDAP ACLs to align with security best practices.

Patching and Updates

Apply security patches and updates provided by UCS@school to address this vulnerability.