CVE-2026-3820 in SMCI AS-2115HS-TNR
Summary
by MITRE • 06/04/2026
There is a vulnerability in the Supermicro BMC SMTP service at Supermicro AS-2115HS-TNR. An attacker may obtain administrator privileges and inject specially crafted characters into the SMTP service configuration. This may cause the underlying system to execute unintended commands during process invocation.
Potential impact includes denial-of-service attacks, arbitrary code execution, or permanent compromise of the controller.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/04/2026
The vulnerability in the Supermicro AS-2115HS-TNR BMC SMTP service represents a critical security flaw that enables unauthorized privilege escalation and command injection capabilities. This issue stems from insufficient input validation within the SMTP configuration handling mechanism, allowing malicious actors to manipulate system parameters through crafted character sequences. The vulnerability specifically affects the Baseboard Management Controller implementation that governs remote system administration functions, creating a persistent attack surface that can be exploited without requiring physical access to the device. The underlying architecture fails to properly sanitize user-supplied data during SMTP service configuration updates, creating opportunities for attackers to inject malicious commands that execute with elevated privileges. This flaw directly relates to CWE-74 which addresses improper neutralization of special elements in output used by a downstream component, and CWE-94 which covers improper control of generation of code. The attack vector operates through the BMC's web interface or remote management protocols where SMTP configuration parameters are processed, making it accessible to attackers with network connectivity to the device.
The technical exploitation of this vulnerability enables attackers to execute arbitrary code with root privileges on the underlying system, effectively compromising the entire BMC environment. When specially crafted characters are injected into the SMTP service configuration, the system's process invocation mechanism interprets these inputs as legitimate commands, leading to unauthorized execution of malicious payloads. The vulnerability's impact extends beyond simple command execution to include potential denial-of-service conditions that can render the BMC inoperable, preventing legitimate administrators from accessing critical system management functions. This compromise of the BMC controller creates a permanent backdoor that can persist across system reboots and updates, providing attackers with long-term access to the device's administrative capabilities. The flaw also enables attackers to manipulate email notifications and system alerts, potentially masking their activities or redirecting security communications to unauthorized parties. The vulnerability's severity is amplified by the fact that BMC systems typically operate with elevated privileges and maintain access to critical system functions, making this a prime target for attackers seeking persistent access to enterprise environments.
The operational impact of this vulnerability creates significant risks for organizations relying on Supermicro hardware for critical infrastructure management. System administrators may experience complete loss of control over affected devices, with potential cascading effects on network availability and security monitoring capabilities. The ability to execute arbitrary code with administrative privileges allows attackers to install persistent malware, modify system configurations, or establish covert communication channels that can evade traditional security controls. Organizations may face regulatory compliance issues if their BMC systems are compromised, particularly in environments governed by standards such as nist 800-53 or soc 2 requirements. The vulnerability also increases the risk of supply chain attacks, as compromised BMC devices can serve as entry points for broader network infiltration. Recovery from such an attack typically requires complete system reinstallation and certificate regeneration, creating significant operational disruption and potential data loss.
Mitigation strategies for this vulnerability should include immediate firmware updates from Supermicro addressing the SMTP configuration validation issues, along with network segmentation to limit access to BMC management interfaces. Organizations should implement strict access controls and authentication mechanisms for BMC systems, including multi-factor authentication and IP address restrictions. Network monitoring should be enhanced to detect unusual SMTP traffic patterns or configuration changes that may indicate exploitation attempts. Regular security assessments of BMC systems should include vulnerability scanning and penetration testing focused on remote management interfaces. The implementation of network access control lists and firewall rules specifically targeting BMC ports can help reduce attack surface exposure. Additionally, organizations should establish incident response procedures specifically designed for BMC compromise scenarios, including protocols for secure system recovery and certificate management. System administrators should regularly review SMTP configuration parameters and implement automated monitoring for unauthorized changes. The vulnerability's remediation aligns with ATT&CK technique T1059 which covers command and scripting interpreter, and T1068 which addresses exploit for privilege escalation. Organizations should also consider implementing network behavioral analysis tools to detect anomalous command execution patterns that may indicate exploitation of this vulnerability.