CVE-2026-9770 in Kasa
Summary
by MITRE • 07/15/2026
Kasa EC71 v4 and EC70 v4 firmware contains a static cryptographic private key stored in a read-only filesystem that is shared across devices. An attacker with access to the firmware image can extract the embedded key.
Successful exploitation may allow an unauthenticated attacker on the same network to use this key in the web management service, compromising the confidentiality of encrypted communications. This may enable passive decryption of traffic or active man-in-the-middle (MITM) attacks
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Analysis
by VulDB Data Team • 07/15/2026
The Kasa EC71 v4 and EC70 v4 firmware implementations contain a critical cryptographic vulnerability stemming from the improper handling of private keys within their software architecture. This flaw represents a fundamental breakdown in security design where a static cryptographic private key is embedded within the read-only filesystem of these network devices, creating a persistent security weakness that affects all units sharing the same firmware version. The presence of such a hardcoded key violates established security principles and creates a single point of failure that undermines the entire cryptographic framework protecting device communications.
The technical implementation of this vulnerability involves the storage of a private key in a location accessible to attackers who can obtain the complete firmware image through various means including network discovery, firmware analysis, or physical access to devices. When a private key is embedded within firmware and shared across multiple devices, it creates a massive security risk where compromising one device effectively compromises all devices using the same firmware version. This specific implementation pattern falls under the CWE-310 cryptographic vulnerability category, specifically addressing weak cryptography issues related to hardcoded keys that should never be exposed in software artifacts.
The operational impact of this vulnerability extends beyond simple confidentiality breaches to enable sophisticated attack vectors including passive decryption of encrypted communications and active man-in-the-middle attacks. An unauthenticated attacker operating within the same network segment can leverage the extracted private key to impersonate legitimate devices, intercept and modify communications between the devices and their management services, or establish persistent access points within the network infrastructure. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under initial access and credential access phases, where attackers exploit hardcoded credentials and cryptographic keys to gain unauthorized system access.
The implications of this vulnerability are particularly severe given that these devices operate as part of home automation ecosystems where they control critical network infrastructure components. The shared nature of the private key across multiple device models means that a single successful extraction can compromise an entire fleet of devices, potentially enabling attackers to control smart home systems, monitor network traffic, and establish persistent backdoors within residential or commercial networks. Organizations implementing these devices face significant risk exposure where the vulnerability creates opportunities for both passive surveillance and active network infiltration attacks.
Mitigation strategies must address the root cause by implementing proper key management practices including the generation of unique device-specific keys during manufacturing processes, the use of secure hardware modules for cryptographic operations, and the implementation of proper firmware update mechanisms that can replace compromised keys. The solution requires moving away from hardcoded cryptographic values to dynamic key generation approaches that ensure each device maintains its own unique cryptographic identity while maintaining the ability to authenticate legitimate communications within the network ecosystem.