Jianjun Chen

Jianjun Chen

Assistant Professor at Tsinghua University working on Network Security

Office: Room 1-213, FIT building, Tsinghua University, Beijing, China

Email: jianjun [AT] tsinghua.edu.cn
jianjun [AT] icsi.berkeley.edu
cjj [AT] cs.uchicago.edu

  I'm looking for self-motivated Ph.D., master and undergradute students! Please feel free to email me.

Me and My Research

I am an assistant professor at the Institute for Network Sciences and Cyberspace at Tsinghua University. Before joining Tsinghua, I was a postdoctoral researcher at UC Berkeley (worked with Prof. Vern Paxson) and the University of Chicago (worked with Prof. Nick Feamster). I received my Ph.D. in Computer Science at Tsinghua University (advised by Prof. Haixin Duan) in 2018.

My research interest focus on network security, protocol security, and system security. I'm particularly interested in discovering and mitigating new security vulnerabilities in widely-used Internet protocols and systems, such as HTTP protocol, CDN system, email system, web browsers.

My research has won Distinguished Paper Awards on the top-tier security conferences (e.g., NDSS 2016 and USENIX security 2020), and led to many real-world security responses, such as patches in popular HTTP implementations (e.g., Squid, Chrome, Firefox), security advisories by industrial companies (e.g., Akamai, Cloudflare, Apple), web standard change, and a new IETF RFC (RFC 8586).


Temporal CDN-Convex Lens: A CDN-Assisted Practical Pulsing DDoS Attack
32th USENIX Conference on Security Symposium
Run Guo, Jianjun Chen, Yihang Wang, Keran Mu, Baojun Liu, Xiang Li, Chao Zhang, Haixin Duan, Jianping Wu
To appear
USENIX Security'23
TsuKing: Coordinating DNS Resolvers and Queries into Potent DoS Amplifiers
30th ACM Conference on Computer and Communications Security
Wei Xu, Xiang Li, Chaoyi Lu, Baojun Liu, Jia Zhang, Jianjun Chen, Tao Wan, Haixin Duan
To appear
Under the Dark: A Systematical Study of Stealthy Mining Pools (Ab)use in the Wild
30th ACM Conference on Computer and Communications Security
Zhenrui Zhang, Geng Hong, Xiang Li, Zhuoqun Fu, Jia Zhang, Mingxuan Liu, Chuhan Wang, Jianjun Chen, Baojun Liu, Haixin Duan, Chao Zhang, Min Yang
To appear
Silence is not Golden: Disrupting the Load Balancing of Authoritative DNS Servers
30th ACM Conference on Computer and Communications Security
Fenglu Zhang, Baojun Liu, Eihal Alowaisheq, Jianjun Chen, Chaoyi Lu, Linjian Song, Yong Ma, Ying Liu, Haixin Duan, Min Yang
To appear
1dFuzz: Reproduce 1-day Vulnerabilities with Directed Differential Fuzzing
32nd ACM SIGSOFT International Symposium on Software Testing and Analysis
Songtao Yang, Yubo He, Kaixiang Chen, Zheyu Ma, Xiapu Luo, Yong Xie, Jianjun Chen, Chao Zhang
To appear
DareShark: Detecting and Measuring Security Risks of Hosting-Based Dangling Domains
Mingming Zhang, Xiang Li, Baojun Liu, Jianyu Lu, Jianjun Chen, Yiming Zhang, Xiaofeng Zheng, Haixin Duan, Shuang Hao
A Security Study about Electron Applications and a Programming Methodology to Tame DOM Functionalities
Proceedings 2023 Network and Distributed System Security Symposium
Zihao Jin, Shuo Chen, Yang Chen, Haixin Duan, Jianjun Chen, Jianping Wu
Callee: Recovering Call Graphs for Binaries with Transfer and Contrastive Learning
2023 IEEE Symposium on Security and Privacy
Wenyu Zhu, Zhiyao Feng, Zihan Zhang, Jianjun Chen, Zhijian Ou, Min Yang, Chao Zhang
A Large-scale and Longitudinal Measurement Study of DKIM Deployment
31th USENIX Conference on Security Symposium
Chuhan Wang, Kaiwen Shen, Minglei Guo, Yuxuan Zhao, Mingming Zhang, Jianjun Chen, Baojun Liu, Xiaofeng Zheng, Haixin Duan, Yanzhong Lin, Qingfeng Pan
USENIX Security'22
HDiff: A Semi-automatic Framework for Discovering Semantic Gap Attack in HTTP Implementations
52nd Annual IEEE/IFIP International Conference on Dependable Systems and Networks
Kaiwen Shen, Jianyu Lu, Yaru Yang, Jianjun Chen, Mingming Zhang, Haixin Duan, Jia Zhang, Xiaofeng Zheng
Best Paper Award Runners Up
Composition Kills: A Case Study of Email Sender Authentication
29th USENIX Conference on Security Symposium
Jianjun Chen,Vern Paxson, Jian Jiang
Invited to appear in USENIX ;login:, 2021(Invited Article)
Presented at BlackHat USA 2020 (talk abstract)
paper slides talk code
Coverage: Wired, CSO online, and Dark reading
USENIX Security'20
Distinguished Paper Award
CDN Judo: Breaking the CDN DoS Protection with Itself
Proceedings 2020 Network and Distributed System Security Symposium
Run Guo, Weizhong Li, Baojun Liu, Shuang Hao, Jia Zhang, Haixin Duan, Kaiwen Sheng, Jianjun Chen,Ying Liu
paper slides
We Still Don’t Have Secure Cross-Domain Requests: an Empirical Study of CORS
27th USENIX Conference on Security Symposium
Jianjun Chen, Jian Jiang, Haixin Duan, Tao Wan, Shuo Chen, Vern Paxson, Min Yang
Presented at DEFCON China 2018 (talk abstract)
paper slides talk code
USENIX Security'18
Abusing CDNs for Fun and Profit: Security Issues in CDNs’ Origin Validation
IEEE 37th Symposium on Reliable Distributed Systems
Run Guo; Jianjun Chen; Baojun Liu; Jia Zhang; Chao Zhang; Haixin Duan; Tao Wan; Jian Jiang; Shuang Hao; Yaoqi Jia;
Forwarding Loop Attacks in Content Delivery Networks
Proceedings 2016 Network and Distributed System Security Symposium
Jianjun Chen; Jian Jiang; Xiaofeng Zheng; Haixin Duan; Jinjin Liang; Kang Li; Tao Wan; Vern Paxson;
Real-world impact: Cloudflare blog, Fastly blog, CERT/CC, RFC 8586
paper slides
Distinguished Paper Award
Host of Troubles: Multiple Host Ambiguities in HTTP Implementations
23rd ACM SIGSAC Conference on Computer and Communications Security
Jianjun Chen, Jian Jiang, Haixin Duan, Nicholas Weaver, Tao Wan, Vern Paxson
paper slides talk website
Best Paper Nominee
Seeking Nonsense, Looking for Trouble: Efficient Promotional-Infection Detection through Semantic Inconsistency Search
2016 IEEE Symposium on Security and Privacy
Xiaojing Liao; Kan Yuan; XiaoFeng Wang; Zhongyu Pei; Hao Yang; Jianjun Chen; Haixin Duan; Kun Du; Eihal Alowaisheq; Sumayah Alrwais; Luyi Xing; Raheem Beyah;

Honors & Awards

  • NSFC Excellent Young Scholar (国家级青年高层次人才)
  • 2022
  • Best Paper Award Runners Up, IEEE/IFIP Dependable Systems and Networks (DSN) 2022
  • 2022
  • Distinguished Paper Award, USENIX Security 2020
  • 2020
  • ACM China SIGSAC Doctoral Dissertation Award
  • 2019
  • Distinguished Paper Award, Network and Distributed System Symposium (NDSS) 2016
  • 2016

    Professional Actitivies

  • Program Committee, IEEE Symposium on Security and Privacy (S&P)
  • 2024
  • Program Committee, ACM Conference on Computer and Communications Security (CCS)
  • 2023
  • Program Committee, ACM Internet Measurement Conference (IMC)
  • 2023
  • Program Committee, IEEE European Symposium on Security and Privacy (Euro S&P)
  • 2023

    Professional Experience

  • Assistant Professor, Tsinghua University
  • Oct 2021 - Present
  • Postdoctoral Fellow, University of Chicago
  • Apr 2021 - Sep 2021
  • Postdoctoral Fellow, UC Berkeley
  • Aug 2018 - Apr 2021