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- All Subjects: static analysis
- Creators: Zhao, Ziming
Description
Web applications are ubiquitous. Accessible from almost anywhere, web applications support multiple platforms and can be easily customized. Most people interact with web applications daily for social media, communication, research, purchases, etc. Node.js has gained popularity as a programming language for web applications. A server-side JavaScript implementation, Node.js, allows both the front-end and back-end to be coded in JavaScript. Node.js contains many features such as dynamic inclusion of other modules using a built-in function named require which dynamically locates and loads code.
To be effective, web applications must perform actions quickly while avoiding unexpected interruptions. However, dynamically linked libraries can cause delays and thus downtime, because dynamically linked code must load multiple files, often from disk. As loading is one of the slowest operations a computer performs, seeking from disk can have a negative impact on performance which causes the server to feel less responsive for users. Dynamically linked code can also break when the underlying library is updated. Normally, when trying to update a server, developers will use test servers. However, if the developer accidentally updates a library in a dynamically linked system, it may be incompatible with another portion of the program.
Statically linking code makes it more reliable and faster (to load) than dynamically linking code. The static linking process varies by programming language. Therefore, different static linkers need to be developed for different languages. This thesis describes the creation of a static linker, called FrozenNode, for the popular back-end web application language, Node.js. FrozenNode resolves Node.js applications into a single file that does not rely on dynamic libraries. FrozenNode was built on top of Closure Compiler to accurately process JavaScript. We found that the resolved application was faster and self-contained yielding significant advantages over the dynamically loaded application. Furthermore, both had the same output.
Vulnerabilities in web applications can be found using static analysis tools, however static analysis tools must reason about dynamically linked application. FrozenNode can be used to statically link a Node.js application before being used by a JavaScript static analysis tool.
To be effective, web applications must perform actions quickly while avoiding unexpected interruptions. However, dynamically linked libraries can cause delays and thus downtime, because dynamically linked code must load multiple files, often from disk. As loading is one of the slowest operations a computer performs, seeking from disk can have a negative impact on performance which causes the server to feel less responsive for users. Dynamically linked code can also break when the underlying library is updated. Normally, when trying to update a server, developers will use test servers. However, if the developer accidentally updates a library in a dynamically linked system, it may be incompatible with another portion of the program.
Statically linking code makes it more reliable and faster (to load) than dynamically linking code. The static linking process varies by programming language. Therefore, different static linkers need to be developed for different languages. This thesis describes the creation of a static linker, called FrozenNode, for the popular back-end web application language, Node.js. FrozenNode resolves Node.js applications into a single file that does not rely on dynamic libraries. FrozenNode was built on top of Closure Compiler to accurately process JavaScript. We found that the resolved application was faster and self-contained yielding significant advantages over the dynamically loaded application. Furthermore, both had the same output.
Vulnerabilities in web applications can be found using static analysis tools, however static analysis tools must reason about dynamically linked application. FrozenNode can be used to statically link a Node.js application before being used by a JavaScript static analysis tool.
ContributorsHutchins, James (Author) / Doupe, Adam (Thesis advisor) / Shoshitaishvili, Yan (Committee member) / Zhao, Ziming (Committee member) / Arizona State University (Publisher)
Created2018
Description
The purpose of this project was to implement and analyze a new proposed rootkit that claims a greater level of stealth by hiding in cache. Today, the vast majority of embedded devices are powered by ARM processors. To protect their processors from attacks, ARM introduced a hardware security extension known as TrustZone. It provides an isolated execution environment within the embedded device that enables us to run various memory integrity and malware detection tools to identify possible breaches in security to the normal world. Although TrustZone provides this additional layer of security, it also adds another layer of complexity, and thus comes with its own set of vulnerabilities. This new rootkit identifies and exploits a cache incoherence in the ARM device as a result of TrustZone. The newly proposed rootkit, called CacheKit, takes advantage of this cache incoherence to avoid memory introspection from tools in secure world. We implement CacheKit on the i.MX53 development board, which features a single ARM Cortex A8 processor, to analyze the limitations and vulnerabilities described in the original paper. We set up the Linux environment on the computer to be able to cross-compile for the development board which will be running the FreeScale android 2.3.4 platform with a 2.6.33 Linux kernel. The project is implemented as a kernel module that once installed on the board can manipulate cache as desired to conceal the rootkit. The module exploits the fact that in TrustZone, the secure world does not have access to the normal world cache. First, a technique known as Cache-asRAM is used to ensure that the rootkit is loaded only into cache of the normal world where it can avoid detection from the secure world. Then, we employ the cache maintenance instructions and resisters provided in the cp15 coprocessor to keep the code persistent in cache. Furthermore, the cache lines are mapped to unused I/O address space so that if cache content is flushed to RAM for inspection, the data is simply lost. This ensures that even if the rootkit were to be flushed into memory, any trace of the malicious code would be lost. CacheKit prevents defenders from analyzing the code and destroys any forensic evidence. This provides attackers with a new and powerful tool that is excellent for certain scenarios that were previously thought to be secure. Finally, we determine the limitations of the prototype to determine possible areas for future growth and research into the security of networked embedded devices.
ContributorsGutierrez Barnett, Mauricio Antonio (Author) / Zhao, Ziming (Thesis director) / Doupe, Adam (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12