CVE-2023-27353 in One Speaker
Summary
by MITRE • 04/21/2023
This vulnerability allows network-adjacent attackers to disclose sensitive information on affected installations of Sonos One Speaker 70.3-35220. Authentication is not required to exploit this vulnerability. The specific flaw exists within the msprox endpoint. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-19846.
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Analysis
by VulDB Data Team • 11/17/2025
The vulnerability identified as CVE-2023-27353 represents a critical information disclosure flaw affecting Sonos One Speaker firmware version 70.3-35220 and potentially other affected models. This vulnerability resides within the msprox endpoint of the device's web server implementation, making it accessible to network-adjacent attackers without requiring any authentication credentials. The flaw stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data before processing, creating a condition where malicious input can cause the system to read beyond the boundaries of allocated memory buffers. This type of vulnerability falls under the common weakness enumeration CWE-125, which specifically addresses out-of-bounds read conditions that can lead to information disclosure and potentially more severe exploitation vectors.
The technical implementation of this vulnerability allows attackers to craft specially formatted requests that trigger buffer over-read conditions when the msprox endpoint processes incoming data. When the system attempts to read data beyond the allocated buffer boundaries, it may inadvertently expose sensitive information stored in adjacent memory locations, including potentially confidential system data, credentials, or other sensitive material. The lack of authentication requirements significantly amplifies the risk, as any network-adjacent attacker can exploit this vulnerability without prior access or credentials. This characteristic aligns with ATT&CK technique T1071.004 for application layer protocol usage and T1566 for malicious code injection through network services.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential pathway for more sophisticated attacks. An attacker who successfully exploits this vulnerability can leverage the exposed memory contents to gather intelligence about the device's internal state, configuration, or running processes. This reconnaissance data can then be combined with other vulnerabilities present in the system to achieve arbitrary code execution with root privileges. The combination of information disclosure followed by privilege escalation represents a classic attack progression pattern that security professionals must consider when assessing the overall risk posture of affected devices. This vulnerability demonstrates how seemingly minor input validation flaws can create significant security risks when combined with other attack vectors.
Mitigation strategies for CVE-2023-27353 should focus on immediate firmware updates provided by Sonos to address the buffer over-read condition in the msprox endpoint. Organizations should also implement network segmentation to limit access to affected Sonos devices to trusted network segments only, reducing the attack surface for adjacent network attackers. Additional defensive measures include monitoring network traffic for suspicious requests targeting the msprox endpoint and implementing intrusion detection systems that can identify patterns associated with this specific vulnerability. The vulnerability highlights the importance of proper input validation and memory safety practices in embedded systems, particularly those with web-based management interfaces. Network administrators should also consider disabling unnecessary web services and ports on Sonos devices when possible, following the principle of least privilege to minimize potential attack vectors. Regular security assessments of IoT devices within enterprise networks are essential to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.