File parsers in Go contain unexpected behaviors that can lead to serious security vulnerabilities. This post examines how JSON, XML, and YAML parsers in Go handle edge cases in ways that have repeatedly resulted in high-impact security issues in production systems. We explore three real-world attack scenarios: marshaling/unmarshaling unexpected data, exploiting parser differentials, and leveraging data format confusion. Through examples, we demonstrate how attackers can bypass authentication, circumvent authorization controls, and exfiltrate sensitive data by exploiting these parser behaviors.
Today, we’re releasing SARIF Explorer, the VSCode extension that we developed to streamline how we triage static analysis results. We make heavy use of static analysis tools during our audits, but the process of triaging them was always a pain. We designed SARIF Explorer to provide an intuitive UI inside VSCode, with […]
tl;dr: Our publicly available Semgrep ruleset has nine new rules to detect misconfigurations of versions 3 and 4 of the Apollo GraphQL server. Try them out with semgrep –config p/trailofbits! When auditing several of our clients’ Apollo GraphQL servers, I kept finding the same issues over and over: cross-site request forgery (CSRF) […]
In part one of this two-part series, we escaped Webviews in real-world misconfigured VSCode extensions. But can we still escape extensions if they are well-configured? In this post, we’ll demonstrate how I bypassed a Webview’s localResourceRoots by exploiting small URL parsing differences between the browser—i.e., the Electron-created Chromium instance where VSCode and […]
TL;DR: This two-part blog series will cover how I found and disclosed three vulnerabilities in VSCode extensions and one vulnerability in VSCode itself (a security mitigation bypass assigned CVE-2022-41042 and awarded a $7,500 bounty). We will identify the underlying cause of each vulnerability and create fully working exploits to demonstrate how an […]
