CVE-2019-0729 in Java SDK for Azure IoT
Summary
by MITRE
An Elevation of Privilege vulnerability exists in the way Azure IoT Java SDK generates symmetric keys for encryption, allowing an attacker to predict the randomness of the key, aka 'Azure IoT Java SDK Elevation of Privilege Vulnerability'.
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Analysis
by VulDB Data Team • 07/26/2023
The Azure IoT Java SDK Elevation of Privilege vulnerability represents a critical security flaw in the cryptographic implementation used for securing Internet of Things devices within Microsoft's cloud ecosystem. This vulnerability specifically targets the symmetric key generation mechanism employed by the SDK, which is utilized by IoT devices to establish secure communications with Azure services. The flaw manifests in the improper implementation of random number generation algorithms that are fundamental to creating secure cryptographic keys. When IoT devices connect to Azure services using the affected SDK, they rely on these symmetric keys for authentication and encryption purposes, making the vulnerability particularly dangerous as it compromises the entire security chain of device-to-cloud communications.
The technical root cause of this vulnerability lies in the weak randomness implementation within the Java SDK's key generation process. The affected implementation fails to properly utilize cryptographically secure random number generators, instead relying on predictable or insufficiently randomized sources. This weakness allows an attacker who gains access to certain information about the key generation process to potentially predict future keys or recover existing ones through mathematical analysis. The vulnerability specifically impacts the symmetric key derivation functions that are used to generate encryption keys for device authentication and data protection. According to CWE-330, this represents a weakness in randomness, where insufficient entropy or predictable seed values lead to cryptographic failures that can be exploited by attackers.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally undermines the security model of IoT deployments using the affected SDK. An attacker who successfully predicts or recovers symmetric keys can gain unauthorized access to IoT devices, potentially enabling them to manipulate device behavior, access sensitive data, or use devices as entry points for broader network attacks. The vulnerability affects the integrity and confidentiality of communications between IoT devices and Azure services, creating opportunities for man-in-the-middle attacks, data exfiltration, and device compromise. This type of vulnerability aligns with ATT&CK technique T1552.001, which covers "Unsecured Credentials" and specifically targets the exploitation of weak cryptographic implementations that can be leveraged to gain unauthorized access to systems.
Organizations utilizing Azure IoT services with the affected Java SDK must implement immediate mitigations to protect their IoT ecosystems. The primary recommendation involves updating to the patched version of the Azure IoT Java SDK where Microsoft has corrected the random number generation implementation to use proper cryptographic random number generators. Additionally, organizations should consider implementing additional monitoring and detection mechanisms to identify potential exploitation attempts, as well as conducting comprehensive security assessments of their IoT deployments. The vulnerability highlights the importance of proper cryptographic implementation in security-critical applications and underscores the need for thorough security testing of all cryptographic components, particularly those used in IoT environments where device compromise can have significant operational and safety implications. Organizations should also review their key management practices and consider implementing key rotation policies to minimize the impact of potential key exposure.