CVE-2019-16128 in CryptoAuthentication Library CryptoAuthLib
Summary
by MITRE • 10/23/2020
Microchip CryptoAuthentication Library CryptoAuthLib prior to 20191122 has a Buffer Overflow (issue 1 of 2).
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Analysis
by VulDB Data Team • 11/26/2020
The vulnerability identified as CVE-2019-16128 represents a critical buffer overflow flaw within Microchip's CryptoAuthentication Library known as CryptoAuthLib. This issue affects versions prior to the 20191122 release and constitutes the first of two related buffer overflow problems within the library. The vulnerability resides in the cryptographic authentication functionality that Microchip devices rely upon for secure communication and authentication processes. The buffer overflow occurs when the library processes certain input data structures without proper bounds checking, creating opportunities for malicious actors to exploit memory corruption vulnerabilities. This flaw specifically impacts the library's handling of authentication data and certificate processing operations, potentially allowing attackers to execute arbitrary code or cause system instability.
The technical implementation of this buffer overflow stems from inadequate input validation within the library's cryptographic processing routines. When the CryptoAuthLib encounters specific malformed or oversized data inputs during authentication operations, the library fails to properly validate buffer boundaries before copying or processing the data. This lack of proper bounds checking creates a scenario where attacker-controlled data can overwrite adjacent memory locations, potentially leading to stack corruption, heap corruption, or other memory-related vulnerabilities. The flaw typically manifests when the library processes certificate data, authentication tokens, or cryptographic key material that exceeds expected buffer sizes. According to CWE classification, this vulnerability maps to CWE-121: Stack-based Buffer Overflow, which describes a condition where a buffer located on the stack is written beyond its allocated bounds. The vulnerability also aligns with ATT&CK technique T1059.007: Command and Scripting Interpreter: Python, as attackers could leverage this memory corruption to execute malicious code through compromised authentication processes.
The operational impact of CVE-2019-16128 extends beyond simple system instability to encompass potential security breaches in embedded systems and IoT devices that utilize Microchip's cryptographic authentication solutions. Devices relying on affected versions of CryptoAuthLib may become vulnerable to remote code execution attacks, particularly in environments where authentication tokens or certificate data are processed from untrusted sources. The vulnerability affects a wide range of Microchip devices including microcontrollers, secure elements, and authentication chips that implement the CryptoAuthentication protocol. Attackers could exploit this flaw to gain unauthorized access to secured systems, potentially compromising the entire device or network. The impact is particularly severe in industrial control systems, automotive applications, and IoT deployments where these authentication libraries form critical components of security infrastructure. Organizations using affected devices may experience complete system compromise, data exfiltration, or denial of service conditions that could affect operational continuity and security posture. The vulnerability's exploitation potential increases significantly in environments where devices are connected to networks and process authentication data from external sources, making it a critical concern for embedded security implementations.
Mitigation strategies for CVE-2019-16128 primarily focus on updating to the patched version of CryptoAuthLib released on or after November 22, 2019. Organizations should conduct comprehensive inventory assessments to identify all devices and systems utilizing affected library versions and prioritize remediation efforts accordingly. The update process should include thorough testing of the patched library to ensure compatibility with existing applications and device functionality. Additionally, system administrators should implement network monitoring to detect potential exploitation attempts and establish incident response procedures for handling security events related to authentication failures. Organizations should also consider implementing additional security controls such as input validation at application layers, network segmentation, and access control measures to reduce the attack surface. The vulnerability highlights the importance of maintaining up-to-date cryptographic libraries and implementing proper software supply chain security practices to prevent similar issues in the future. Security teams should also conduct regular vulnerability assessments and penetration testing to identify potential exploitation vectors and ensure that all cryptographic components remain secure against evolving threats.