The developers of MatrixSSL have released an update that addresses several vulnerabilities, including ones that could be exploited to take complete control of systems.
MatrixSSL is a high-performance SSL/TLS implementation that is ideal for Internet of Things (IoT) devices thanks to its low memory footprint. The product is used by several major companies, including Canon, D-Link, Intel, Ixia and Motorola.
Tripwire researcher Craig Young and Andreas Walz of the University of Applied Sciences Offenburg, Germany, discovered several critical issues. Young found vulnerabilities in the MatrixSSL X.509 certificate handling code through a fuzz testing with the American Fuzzy Lop (AFL) tool from Google’s Michal Zalewski.
In a blog post published on Monday, the researcher explained that he identified three memory safety issues, including an exploitable heap buffer overflow (CVE-2016-6890), a buffer overread (CVE-2016-6891), and a bug related to the x509FreeExtensions() function (CVE-2016-6892).
“Systems using MatrixSSL to process untrusted X.509 certificates, such as what might happen if a certificate is sent for client authentication, could be prone to remote unauthenticated code execution in the context of the SSL stack,” Young warned. “In the case of a router or other IoT devices, this almost certainly means an attacker could gain complete control of an affected system as the root user.”
Young decided to analyze MatrixSSL after a discussion with researcher Hanno Böck, who in July was credited by MatrixSSL developers for finding a critical flaw.
The vulnerabilities found by Young and Walz were patched on Monday with the release of MatrixSSL 3.8.6. Young said the vendor informed certain embedded device manufacturers in September and they should release updates soon if they haven’t done so already.
On the other hand, the researcher is concerned that many devices running the vulnerable MatrixSSL code will likely never be patched, either because their vendors don’t release security fixes or because users don’t install them. He believes that these types of vulnerabilities highlight the need for better IoT update practices.
“If you are reading this as a vendor, my advice is to focus on building devices with better update mechanisms and development practices to support quick delivery,” Young said. “Consumers, on the other hand, need to press vendors toward long-term support commitments for the embedded devices they buy.”
Vulnerabilities that allow attackers to compromise IoT devices can be exploited by botnets designed for distributed denial-of-service (DDoS) attacks. Unfortunately, there are millions of Internet-exposed devices that can be easily abused by cybercriminals for such campaigns.
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