CVE-2025-68435 in zerobyte
Summary
by MITRE • 12/18/2025
Zerobyte is a backup automation tool Zerobyte versions prior to 0.18.5 and 0.19.0 contain an authentication bypass vulnerability where authentication middleware is not properly applied to API endpoints. This results in certain API endpoints being accessible without valid session credentials. This is dangerous for those who have exposed Zerobyte to be used outside of their internal network. A fix has been applied in both version 0.19.0 and 0.18.5. If immediate upgrade is not possible, restrict network access to the Zerobyte instance to trusted networks only using firewall rules or network segmentation. This is only a temporary mitigation; upgrading is strongly recommended.
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Analysis
by VulDB Data Team • 12/18/2025
The vulnerability identified as CVE-2025-68435 affects Zerobyte backup automation software versions prior to 0185 and 0190, representing a critical authentication bypass flaw that undermines the security posture of the application. This vulnerability stems from improper implementation of authentication middleware within the application programming interface endpoints, creating a scenario where unauthorized users can access sensitive functionality without valid session credentials. The flaw specifically targets the authentication layer that should normally validate user identities and session tokens before granting access to protected resources, thereby exposing the backup automation system to potential exploitation by malicious actors.
The technical nature of this vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems, and demonstrates how inadequate access control mechanisms can create persistent security weaknesses. When Zerobyte instances are exposed to external networks or untrusted environments, this authentication bypass creates a significant attack surface that allows threat actors to manipulate backup operations, potentially leading to data exfiltration, system compromise, or unauthorized access to backup storage locations. The vulnerability's impact is particularly severe in environments where the application serves as a critical component of data protection infrastructure, as it directly undermines the integrity and confidentiality of backup operations.
The operational implications of this vulnerability extend beyond simple unauthorized access, as it enables attackers to potentially disrupt backup processes, modify backup configurations, or gain access to sensitive data that should remain protected. In enterprise environments where backup systems are often treated as trusted components, this vulnerability could allow adversaries to establish persistence or escalate privileges through manipulation of backup automation workflows. The risk is amplified when considering that backup systems typically contain valuable historical data and system configurations that can be leveraged for further attacks or ransomware operations.
Security practitioners should note that while network segmentation and firewall rules can provide temporary mitigation by restricting access to trusted networks, this approach does not address the underlying authentication flaw and remains a stopgap measure. The recommended remediation involves immediate upgrade to versions 0190 or 0185, which contain the necessary patches to properly enforce authentication middleware across all API endpoints. Organizations without immediate upgrade capabilities should implement additional controls such as VPN access restrictions, IP whitelisting, and enhanced monitoring of API access patterns to detect potential exploitation attempts. The vulnerability's classification as a persistent authentication bypass aligns with ATT&CK technique T1078 which covers valid accounts and credential access, making it particularly dangerous for maintaining long-term unauthorized access to backup infrastructure.