CVE-2018-20946 in cPanel
Summary
by MITRE
cPanel before 68.0.27 allows attackers to read zone information because a world-readable archive is created by the archive_sync_zones script (SEC-355).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2018-20946 affects cPanel versions prior to 68.0.27 and represents a critical information disclosure flaw that stems from improper file permissions within the archive_sync_zones script. This vulnerability exposes zone information to unauthorized users through the creation of world-readable archives, fundamentally undermining the security posture of affected systems. The issue manifests when the script generates archive files containing DNS zone data, which are then made accessible to all users on the system due to inadequate permission settings.
The technical root cause of this vulnerability lies in the improper handling of file permissions during the zone synchronization process. When the archive_sync_zones script executes, it creates archive files that are configured with world-readable permissions, allowing any user on the system to access the contents. This flaw directly maps to CWE-732, which describes inadequate permissions for critical resources, and represents a classic example of insecure default configurations. The vulnerability enables attackers to obtain sensitive DNS zone information including domain names, IP addresses, and potentially other configuration details that would normally be restricted to authorized system administrators.
The operational impact of this vulnerability extends beyond simple information disclosure, as DNS zone data can provide attackers with comprehensive insights into network infrastructure, domain relationships, and potential attack vectors. An attacker who gains access to these zone files can identify internal hostnames, service endpoints, and network topology information that significantly aids in subsequent reconnaissance activities. This information can be leveraged for targeted attacks including service enumeration, credential harvesting, and social engineering campaigns. The vulnerability also aligns with ATT&CK technique T1082, which covers system information discovery, and T1566, which covers credential access through social engineering, as the disclosed information can be used to craft more effective attacks.
Mitigation strategies for this vulnerability require immediate patching to cPanel version 68.0.27 or later, which addresses the improper file permission handling in the archive_sync_zones script. System administrators should also conduct thorough audits of file permissions on existing archive files to ensure no sensitive data remains accessible to unauthorized users. Additional protective measures include implementing proper access controls, monitoring for unauthorized access to zone files, and establishing automated alerts for suspicious file access patterns. Organizations should also review their overall DNS security posture and consider implementing additional controls such as DNSSEC to further protect against information disclosure attacks. The vulnerability demonstrates the critical importance of proper permission management in system administration and highlights the need for regular security assessments of automated scripts that handle sensitive data.