A Preliminary Study on Sensitive Information Exposure Through Logging

Logging is a common practice to collect valuable runtime information about software systems. However, information written to log files can be sensitive and give valuable guidance to attackers. In fact, information exposure through logging is not uncommon. Even large-scale online services (e.g., Facebook and Twitter) have reported exposing sensitive information via log files, and hundreds of millions of users are affected. Despite the severity of such vulnerabilities, there is no existing work that studies such vulnerabilities in the real-world context, and we have little knowledge about them. To fill this gap, we conduct a preliminary study on 413 real-world vulnerabilities to investigate the exploitability and root causes of such vulnerabilities. By analyzing these vulnerabilities, we find that 1) about two-third (67.8%) vulnerabilities can be exploited via the network, and a significant amount (89.3%) of vulnerabilities can be exploited with low efforts; 2) malicious users and insiders can use about half of (46.9%) proof-of-concept exploits to launch attacks without any expertise; 3) the top three common root causes for the vulnerabilities are insecure whole-object logging (43.4%), incorrect permission assignment (17.5%), and improper implementation of sanitization (11.2%). Based on the findings, we also discuss the implications for researchers and practitioners. We believe our work can inspire further work on detecting and fixing the vulnerabilities.