CVE-2023-5255 in Puppet Server
Summary
by MITRE • 10/25/2023
For certificates that utilize the auto-renew feature in Puppet Server, a flaw exists which prevents the certificates from being revoked.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/20/2025
The vulnerability identified as CVE-2023-5255 affects Puppet Server implementations that utilize auto-renew certificate functionality, creating a critical weakness in the certificate management infrastructure. This flaw represents a significant deviation from standard certificate lifecycle management practices where certificates should be properly revoked when they are no longer valid or when security concerns arise. The issue specifically impacts systems that rely on automated certificate renewal processes, which are commonly deployed in enterprise environments to maintain continuous service availability and security compliance.
The technical flaw manifests in the certificate revocation mechanism within Puppet Server's auto-renew feature, where the system fails to properly invalidate or remove certificates from the certificate revocation list when renewal processes occur. This creates a persistent security risk where compromised or expired certificates may continue to operate within the system, potentially allowing unauthorized access or privilege escalation attacks. The vulnerability stems from inadequate integration between the certificate renewal and revocation components, resulting in a logical inconsistency in the certificate management workflow. This type of flaw commonly falls under CWE-295 which addresses improper certificate validation or handling, and can be classified as a certificate lifecycle management failure within the context of certificate-based authentication systems.
The operational impact of this vulnerability extends beyond simple certificate management issues, as it fundamentally compromises the security posture of systems relying on Puppet Server for configuration management and infrastructure automation. Organizations utilizing auto-renew certificates may experience extended periods of exposure where compromised certificates remain active in the system, potentially allowing attackers to maintain persistent access or conduct man-in-the-middle attacks against services that depend on these certificates. The vulnerability particularly affects environments where certificate compromise detection and response procedures are automated, as the system fails to properly execute the revocation process that would normally occur during certificate renewal. This creates a window of opportunity for attackers to exploit the system while the compromised certificates remain valid in the certificate store.
Mitigation strategies for CVE-2023-5255 should prioritize immediate implementation of manual certificate revocation procedures for affected systems, combined with enhanced monitoring of certificate usage patterns to detect potential compromise. Organizations should implement additional certificate validation controls and consider deploying certificate monitoring solutions that can detect when certificates are not properly revoked during renewal processes. The remediation approach must include updating Puppet Server to versions that address this specific certificate handling flaw, while also establishing more robust certificate lifecycle management policies that do not rely solely on automated renewal without proper revocation mechanisms. Security teams should also implement periodic certificate audits to identify any certificates that may have been improperly retained in the system. This vulnerability aligns with ATT&CK technique T1552.001 which covers credentials from password stores, as the continued operation of compromised certificates can effectively provide attackers with persistent access to systems. The issue demonstrates the importance of comprehensive certificate management strategies that account for all phases of certificate lifecycle including proper revocation procedures, particularly in automated environments where certificate management processes may not be adequately tested for edge cases.