VLDB 2026 Research / reviewers in the wild / expert
Andreas Happe
dblp:175/5799
· DBLP profile ↗
8ranked-venue papers
6as first author
5since 2021 · last 2026
0009-0000-2484-0109ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Software engineering, systems software and programming languages · 5 · 4 first-author · 5 since 2021Security and privacy · 1 · 1 first-authorDatabases, data management, data science and information retrieval · 1 · 1 since 2021Theory of computation · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Adversarial Bug Reports as a Security Risk in Language Model-Based Automated Program RepairabstractLarge Language Model (LLM) - based Automated Program Repair (APR) systems are increasingly integrated into modern software development workflows, offering automated patches in response to natural language bug reports. However, this reliance on untrusted user input introduces a novel and underexplored attack surface. In this paper, we investigate the security risks posed by adversarial bug reports—realistic-looking issue submissions crafted to mislead APR systems into producing insecure or harmful code changes. We develop a comprehensive threat model and conduct an empirical study to evaluate the vulnerability of APR systems to such attacks. Our demonstration comprises 51 adversarial bug reports generated across a spectrum of strategies, ranging from manual curation to fully automated pipelines. We test these against a leading LLM-based APR system and assess both pre-repair defenses (e.g., LlamaGuard variants, PromptGuard variants, Granite-Guardian, and custom LLM filters) and post-repair detectors (GitHub Copilot, CodeQL). Our findings show that current defenses are insufficient: 90% of crafted bug reports triggered attacker-aligned patches. The best pre-repair filter blocked only 47%, while post-repair analysis—often requiring human oversight—was effective in just 58% of cases. To support scalable security testing, we introduce a prototype framework for automating the generation of adversarial bug reports. Our analysis exposes a structural asymmetry: generating adversarial inputs is inexpensive, while detecting or mitigating them remains costly and error-prone. We conclude with recommendations for improving the robustness of APR systems against adversarial misuse and highlight directions for future work on secure APR. Piotr Przymus, Andreas Happe, Jürgen Cito |
MSR | 2 |
| 2026 | LLMs as Hackers: Autonomous Linux Privilege Escalation AttacksabstractAbstract Penetration-testing is crucial for identifying and mitigating system vulnerabilities, with privilege-escalation being a critical subtask involving gaining elevated access to protected resources. The emergence of Large Language Models (LLMs) presents new avenues for automating these security practices by emulating human behavior. However, a comprehensive understanding of LLMs’ efficacy and limitations in performing autonomous Linux privilege-escalation attacks remains underexplored. To address this gap, we introduce hackingBuddyGPT , a fully automated LLM-driven prototype designed for evaluating autonomous Linux privilege-escalation. We curated a novel, publicly available Linux privilege-escalation benchmark comprising distinct, single-vulnerability virtual machines, enabling controlled and reproducible evaluation. Our empirical analysis assesses the quantitative success rates and qualitative operational behaviors of various LLMs— GPT-3.5-Turbo , GPT-4-Turbo , and Llama3 —against baselines of human professional penetration-testers and traditional automated tools. We investigate the impact of context management strategies, different context sizes, and various high-level guidance mechanisms on LLM performance. Results show that GPT-4-Turbo demonstrates high efficacy, successfully exploiting 33–83% of vulnerabilities, a performance comparable to human penetration testers (75%). In contrast, local models like Llama3 exhibited limited success (0–33%), and GPT-3.5-Turbo achieved moderate rates (16–50%). High-level guidance significantly boosts LLM success rates , for instance when using GPT-4-Turbo from 33% to 66% (without guidance) or from 66% to 83%, while state management through LLM-driven reflection doubled unaided GPT-4-Turbo success rates (from 33% to 66%). Qualitative analysis reveals both LLMs’ strengths and weaknesses in generating valid commands and highlights challenges in common-sense reasoning, error handling, and multi-step exploitation, particularly with temporal dependencies. Cost analysis indicates that GPT-4-Turbo can achieve human-comparable performance at competitive costs per exploited vulnerability, especially with optimized context management. Our work provides a baseline for evaluating LLM capabilities in autonomous privilege escalation, guiding future research toward more effective and reliable LLM-guided penetration-testing. Andreas Happe, Aaron Kaplan, Jürgen Cito |
Empir. Softw. Eng. | 1 |
| 2026 | Can LLMs Hack Enterprise Networks? Autonomous Assumed Breach Penetration-Testing Active Directory NetworksabstractTraditional enterprise penetration-testing, while critical for validating defenses and uncovering vulnerabilities, is often limited by high operational costs and the scarcity of human expertise. This article investigates the feasibility and effectiveness of using Large Language Model (LLM)-driven autonomous systems to address these challenges in real-world Active Directory (AD) enterprise networks. We introduce a novel prototype, cochise , designed to employ LLMs to autonomously perform Assumed Breach penetration-testing against enterprise networks. Our system represents the first demonstration of a fully autonomous, LLM-driven framework capable of compromising accounts within a real-life Microsoft Active Directory testbed, the Game of Active Directory (GOAD). The evaluation deliberately utilizes GOAD to capture the intricate interactions and sometimes nondeterministic outcomes of live network penetration-testing, moving beyond the limitations of synthetic benchmarks. We perform our empirical evaluation using five LLMs, comparing reasoning to non-reasoning models as well as including open-weight models. Through comprehensive quantitative and qualitative analysis, incorporating insights from cybersecurity experts, we demonstrate that autonomous LLMs can effectively conduct Assumed Breach simulations. Key findings highlight their ability to dynamically adapt attack strategies, perform inter-context attacks (e.g., web application audits, social engineering, and unstructured data analysis for credentials), and generate scenario-specific attack parameters like realistic password candidates. The prototype also exhibits robust self-correction mechanisms, automatically installing missing tools and rectifying invalid command generations. Critically, we find that the associated costs are competitive with, and often significantly lower than, those incurred by professional human penetration testers, suggesting a path toward democratizing access to essential security testing for organizations with budgetary constraints. However, our research also illuminates existing limitations, including instances of LLM “going down rabbit holes,” challenges in comprehensive information transfer between planning and execution modules, and critical safety concerns that necessitate human oversight. Our findings lay foundational groundwork for future software engineering research into LLM-driven cybersecurity automation, emphasizing that the prototype’s underlying LLM-driven architecture and techniques are domain-agnostic and hold promise for improving autonomous LLM usage in broader software engineering domains. The source code, traces, and analyzed logs are open-sourced to foster collective cybersecurity and future research. Andreas Happe, Jürgen Cito |
ACM Trans. Softw. Eng. Methodol. | 1 |
| 2023 | Understanding Hackers' Work: An Empirical Study of Offensive Security PractitionersabstractOffensive security-tests are commonly employed to pro-actively discover potential vulnerabilities. They are performed by specialists, also known as penetration-testers or white-hat hackers. The chronic lack of available white-hat hackers prevents sufficient security test coverage of software. Research into automation tries to alleviate this problem by improving the efficiency of security testing. To achieve this, researchers and tool builders need a solid understanding of how hackers work, their assumptions, and pain points. Andreas Happe, Jürgen Cito |
ESEC/SIGSOFT FSE | 1 |
| 2023 | Getting pwn'd by AI: Penetration Testing with Large Language ModelsabstractThe field of software security testing, more specifically penetration testing, requires high levels of expertise and involves many manual testing and analysis steps. This paper explores the potential use of large-language models, such as GPT3.5, to augment penetration testers with AI sparring partners. We explore two distinct use cases: high-level task planning for security testing assignments and low-level vulnerability hunting within a vulnerable virtual machine. For the latter, we implemented a closed-feedback loop between LLM-generated low-level actions with a vulnerable virtual machine (connected through SSH) and allowed the LLM to analyze the machine state for vulnerabilities and suggest concrete attack vectors which were automatically executed within the virtual machine. We discuss promising initial results, detail avenues for improvement, and close deliberating on the ethics of AI sparring partners. Andreas Happe, Jürgen Cito |
ESEC/SIGSOFT FSE | 1 |
| 2017 | The Archistar Secret-Sharing Backup ProxyabstractCloud-Storage has become part of the standard toolkit for enterprise-grade computing. While being cost- and energy-efficient, cloud storage's availability and data confidentiality can be problematic. A common approach of mitigating those issues are cloud-of-cloud solutions. Another challenge is the integration of such a solution into existing legacy systems. This paper introduces the Archistar Backup Proxy which allows integration of multi-cloud storage into existing legacy enterprise computing landscapes by overloading the industry-standard Amazon S3 protocol. The paper provides multiple lessons-learned during implementation and concludes with a performance evaluation with traditional backup solutions utilizing redundant remote storage. Andreas Happe, Florian Wohner, Thomas Lorünser |
ARES | 1 |
| 2017 | Unikernels for Cloud Architectures: How Single Responsibility can Reduce Complexity, Thus Improving Enterprise Cloud SecurityabstractACKNOWLEDGEMENTS This work was in part funded by the European Commission through grant agreement no 644962 (PRISMACLOUD). Andreas Happe, Bob Duncan, Alfred Bratterud |
COMPLEXIS | 1 |
| 2015 | ARCHISTAR: Towards Secure and Robust Cloud Based Data SharingabstractCloud based collaboration gives rise to many new applications and business opportunities in both the private and the business domain. However, building such systems in a secure and robust manner is a challenging task. In this paper, we present a new architecture for secure cloud based data sharing called ARCHISTAR. It builds upon a distributed storage system and thus avoids any single point of trust or failure. Besides providing confidentiality of data, our focus is on availability and in particular on robustness against active attacks or failures. Our system provides full multi-user support and enables advanced sharing scenarios without complex key management and revocation mechanisms. We also present a prototype implementation of the ARCHISTAR system and discuss open issues. Thomas Lorünser, Andreas Happe, Daniel Slamanig |
CloudCom | 2 |