Session 13A: JavaScript Security

Authors, Creators & Presenters: Liam Wachter (EPFL), Julian Gremminger (EPFL), Christian Wressnegger (Karlsruhe Institute of Technology (KIT)), Mathias Payer (EPFL), Flavio Toffalini (EPFL)

PAPER
DUMPLING: Fine-Grained Differential JavaScript Engine Fuzzing

Web browsers are ubiquitous and execute untrusted JavaScript (JS) code. JS engines optimize frequently executed code through just-in-time (JIT) compilation. Subtly conflicting assumptions between optimizations frequently result in JS engine vulnerabilities. Attackers can take advantage of such diverging assumptions and use the flexibility of JS to craft exploits that produce a miscalculation, remove bounds checks in JIT compiled code, and ultimately gain arbitrary code execution. Classical fuzzing approaches for JS engines only detect bugs if the engine crashes or a runtime assertion fails. Differential fuzzing can compare interpreted code against optimized JIT compiled code to detect differences in execution. Recent approaches probe the execution states of JS programs through ad-hoc JS functions that read the value of variables at runtime. However, these approaches have limited capabilities to detect diverging executions and inhibit optimizations during JIT compilation, thus leaving JS engines under-tested. We propose DUMPLING, a differential fuzzer that compares the full state of optimized and unoptimized execution for arbitrary JS programs. Instead of instrumenting the JS input, DUMPLING instruments the JS engine itself, enabling deep and precise introspection. These extracted fine-grained execution states, coined as (frame) dumps, are extracted at a high frequency even in the middle of JIT compiled functions. DUMPLING finds eight new bugs in the thoroughly tested V8 engine, where previous differential fuzzing approaches struggled to discover new bugs. We receive $11,000 from Google's Vulnerability Rewards Program for reporting the vulnerabilities found by DUMPLING.

ABOUT NDSS
The Network and Distributed System Security Symposium (NDSS) fosters information exchange among researchers and practitioners of network and distributed system security. The target audience includes those interested in practical aspects of network and distributed system security, with a focus on actual system design and implementation. A major goal is to encourage and enable the Internet community to apply, deploy, and advance the state of available security technologies.

Our thanks to the Network and Distributed System Security (NDSS) Symposium for publishing their Creators, Authors and Presenter’s superb NDSS Symposium 2025 Conference content on the Organizations' YouTube Channel.

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Session 13A: JavaScript Security

Authors, Creators & Presenters: Darion Cassel (Carnegie Mellon University), Nuno Sabino (IST & CMU), Min-Chien Hsu (Carnegie Mellon University), Ruben Martins (Carnegie Mellon University), Limin Jia (Carnegie Mellon University)

PAPER
NodeMedic-FINE: Automatic Detection and Exploit Synthesis for Node.js Vulnerabilities

The Node.js ecosystem comprises millions of packages written in JavaScript. Many packages suffer from vulnerabilities such as arbitrary code execution (ACE) and arbitrary command injection (ACI). Prior work has developed automated tools based on dynamic taint tracking to detect potential vulnerabilities, and to synthesize proof-of-concept exploits that confirm them, with limited success. One challenge these tools face is that expected inputs to package APIs often have varied types and object structure. Failure to call these APIs with inputs of the correct type and with specific fields leads to unsuccessful exploit generation and missed vulnerabilities. Generating inputs that can successfully deliver the desired exploit payload despite manipulation performed by the package is also difficult. To address these challenges, we use a type and object-structure aware fuzzer to generate inputs to explore more execution paths during dynamic taint analysis. We leverage information generated by the taint analysis to infer the types and structure of the inputs, which are then used by the exploit synthesis engine to guide exploit generation. We implement NodeMedic-FINE and evaluate it on 33,011 npm packages that contain calls to ACE and ACI sinks. Our tool finds 2257 potential flows and automatically synthesizes working exploits in 766 packages.

ABOUT NDSS
The Network and Distributed System Security Symposium (NDSS) fosters information exchange among researchers and practitioners of network and distributed system security. The target audience includes those interested in practical aspects of network and distributed system security, with a focus on actual system design and implementation. A major goal is to encourage and enable the Internet community to apply, deploy, and advance the state of available security technologies.

Our thanks to the Network and Distributed System Security (NDSS) Symposium for publishing their Creators, Authors and Presenter’s superb NDSS Symposium 2025 Conference content on the Organizations' YouTube Channel.

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The post NDSS 2025 – NodeMedic-FINE: Automatic Detection And Exploit Synthesis For Node.js Vulnerabilities appeared first on Security Boulevard.