CVE-2025-40596 in SMA 100
Summary
by MITRE • 07/23/2025
A Stack-based buffer overflow vulnerability in the SMA100 series web interface allows remote, unauthenticated attacker to cause Denial of Service (DoS) or potentially results in code execution.
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Analysis
by VulDB Data Team • 07/25/2025
The CVE-2025-40596 vulnerability represents a critical stack-based buffer overflow flaw within the web interface of SMA100 series devices, exposing organizations to significant security risks. This vulnerability specifically affects the web-based management interface of solar power monitoring equipment manufactured by SMA, a leading provider of solar inverter and energy management solutions. The flaw exists in the processing of incoming HTTP requests through the web interface, where insufficient input validation allows attackers to manipulate buffer boundaries and potentially overwrite adjacent memory locations. The vulnerability's severity is compounded by its accessibility, as it requires no authentication credentials for exploitation, making it particularly dangerous for devices deployed in network-accessible environments.
The technical implementation of this buffer overflow stems from improper handling of user-supplied input within the web server component of the SMA100 series devices. When processing HTTP requests containing specially crafted payloads, the device fails to properly validate the length of input parameters, particularly in form fields or URL parameters. This allows an attacker to exceed the allocated stack buffer space, leading to memory corruption that can result in unpredictable behavior. The stack-based nature of the vulnerability means that the overflow occurs in the program's stack memory segment, potentially overwriting return addresses, function pointers, or other critical control data. According to CWE-121, this vulnerability maps directly to stack-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent memory locations, creating opportunities for arbitrary code execution or system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable complete system compromise. Remote attackers can leverage this vulnerability to cause denial of service by crashing the web interface, rendering the device inaccessible for legitimate management purposes, or by triggering system reboots that disrupt solar power generation monitoring. More critically, the vulnerability may allow for code execution if attackers can carefully craft payloads that overwrite program control flow, potentially enabling them to gain unauthorized access to the device's operating system. This represents a significant risk for solar installations where continuous monitoring and control are essential for optimal energy production and grid integration. The vulnerability's impact is particularly concerning given that SMA100 series devices are commonly deployed in both residential and commercial solar installations, where system uptime and reliability are paramount for energy production optimization.
Organizations must implement immediate mitigation strategies to protect their SMA100 series installations from exploitation of this vulnerability. Network segmentation should be implemented to isolate these devices from general network access, with access restricted to authorized personnel only through secure remote access solutions. The most effective immediate solution involves applying manufacturer-provided firmware updates that address the buffer overflow condition through proper input validation and memory boundary checks. Security teams should also implement network monitoring solutions to detect suspicious traffic patterns that may indicate exploitation attempts, particularly focusing on malformed HTTP requests targeting the web interface. According to ATT&CK framework's T1210 technique, this vulnerability represents an attack vector that could be leveraged for privilege escalation or lateral movement within affected networks, making proactive detection and remediation essential. Additionally, organizations should conduct thorough vulnerability assessments of their entire solar energy infrastructure to identify other potentially affected devices and ensure comprehensive security coverage across all monitoring and control systems.