CVE-2018-16528 in Web Services FreeRTOS
Summary
by MITRE
Amazon Web Services (AWS) FreeRTOS through 1.3.1 allows remote attackers to execute arbitrary code because of mbedTLS context object corruption in prvSetupConnection and GGD_SecureConnect_Connect in AWS TLS connectivity modules.
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Analysis
by VulDB Data Team • 04/18/2020
This vulnerability resides in the AWS FreeRTOS implementation where mbedTLS context objects become corrupted during the prvSetupConnection and GGD_SecureConnect_Connect functions within the AWS TLS connectivity modules. The flaw represents a critical security issue that enables remote code execution through improper handling of cryptographic context data structures. The vulnerability affects AWS FreeRTOS versions through 1.3.1 and stems from inadequate memory management during TLS handshake operations, creating opportunities for attackers to manipulate the mbedTLS library state.
The technical implementation involves the corruption of mbedTLS context objects which are fundamental data structures used for maintaining cryptographic session state during TLS connections. When the prvSetupConnection and GGD_SecureConnect_Connect functions execute, they fail to properly initialize or validate the TLS context objects before use, allowing attackers to inject malicious data that corrupts these objects. This corruption can occur through crafted network packets or manipulated connection parameters that cause the TLS library to behave unpredictably during secure communication establishment.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code on affected devices without requiring physical access or authentication. This represents a privilege escalation vulnerability where an attacker can leverage the corrupted TLS context to gain control over the device's execution environment. The vulnerability affects IoT devices running AWS FreeRTOS that rely on secure connections for communication with AWS services, potentially enabling full device compromise and unauthorized access to sensitive data.
Mitigation strategies should focus on immediate patching of affected AWS FreeRTOS versions to 1.4.0 or later where the TLS context handling has been corrected. Organizations should also implement network segmentation and monitoring to detect unusual connection patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflow and memory corruption issues, while also mapping to ATT&CK techniques involving privilege escalation and remote code execution through network-based attacks. Additional defensive measures include disabling unnecessary TLS features, implementing proper input validation for connection parameters, and conducting regular security assessments of IoT device configurations to ensure proper TLS implementation practices are maintained.