Continuous Integration (CI) has been widely adopted for automated software building and testing. In CI workflows, various third-party services can be integrated to enhance functionalities. During the integration process, secrets such as tokens and credentials are often used for authentication and authorization. Unfortunately, secret leakage regularly occurs, potentially causing serious consequences. Existing secret scanners detect secrets by matching tokens and credentials through regular expressions, which suffer from low recall rates. In this paper, we identify several issues in regular expression-based secret detectors and propose SecretScout, a new method for scanning hard-coded secrets by detecting their names. SecretScout contains carefully designed detectors to extract candidates. It considers special flags where secrets might exist, and further applies filters to reduce false positives. SecretScout can detect secrets in both structured files (e.g., CI configuration files) and unstructured files (e.g., log files). To demonstrate the effectiveness, we evaluate SecretScout and different versions of GitLeaks and TruffleHog using labeled configuration files. The results show that SecretScout achieves$7.3 \times$and$100 \times$higher recall rates compared to the default versions of GitLeaks and TruffleHog, respectively. We also conduct a measurement study on open-source projects' configuration files, and demonstrate that many true secrets might be leaked.

Mainstream Continuous Integration (CI) platforms have provided the plugin functionality to accelerate the development of CI pipelines. Unfortunately, CI plugins, which are essentially reusable code snippets, also expose new attack surfaces as plugins might be developed by less trusted users. In this paper, we present an in-depth study to understand potential security risks in existing CI plugins. We conduct a comprehensive analysis of plugin implementations on four mainstream CI platforms (GitHub Actions, GitLab CI, CircleCI, and Azure Pipelines), and investigate several weak links in existing plugin distributions and isolation mechanisms. We investigate seven attack vectors that can enable attackers to hijack plugins and distribute malicious code without plugins users being aware, and further exploit hijacked plugins to manipulate the workflow execution. Additionally, we find that plugin dependency (a plugin references other plugins) might further amplify the attack impact of our disclosed attacks. To evaluate the potential impact, we conduct a large-scale measurement on GitHub and GitLab, covering a total of 1,328,912 repositories using the aforementioned CI platforms. Our measurement results show that a large number of repositories and existing plugins, including many widely used ones, are potentially vulnerable to the proposed attacks. We have duly reported the identified vulnerabilities and received positive responses.

Upgradeable smart contracts (USCs) have been widely adopted to enable modifying deployed smart contracts. While USCs bring great flexibility to developers, improper usage might introduce new security issues, potentially allowing attackers to hijack USCs and their users. In this paper, we conduct a large-scale measurement study to characterize USCs and their security implications in the wild. We summarize six commonly used USC patterns and develop a tool, USCDetector, to identify USCs without needing source code. Particularly, USCDetector collects various information such as bytecode and transaction information to construct upgrade chains for USCs and disclose potentially vulnerable ones. We evaluate USCDetector using verified smart contracts (i.e., with source code) as ground truth and show that USCDetector can achieve high accuracy with a precision of 96.26%. We then use USCDetector to conduct a large-scale study on Ethereum, covering a total of 60,251,064 smart contracts. USCDetecor constructs 10,218 upgrade chains and discloses multiple real-world USCs with potential security issues.

Software-Defined Networking (SDN) enables the deployment of diversified networking applications by providing global visibility and open programmability on a centralized controller. As SDN enters its second decade, several well-developed open source controllers have been widely adopted in industry, and various commercial SDN applications are built to meet the surging demand of network innovation. This complex ecosystem inevitably introduces new security threats, as malicious applications can significantly disrupt network operations. In this paper, we introduce a new vulnerability in existing SDN controllers that enable adversaries to create a backdoor and further deploy malicious applications to disrupt network service via a series of topology poisoning attacks. The root cause of this vulnerability is that SDN systems simply process received Packet-In messages without checking the integrity, and thus can be misguided by manipulated messages. We discover that five popular SDN controllers (i.e., Floodlight, ONOS, OpenDaylight, POX and Ryu) are potentially vulnerable to the disclosed attack, and further propose six new attacks exploiting this vulnerability to disrupt SDN services from different layers. We evaluate the effectiveness of these attacks with experiments in real SDN testbeds, and discuss feasible countermeasures.