Years ago, Java could be used on websites trough applets. To make these applets secure and not let them access files or do other dangerous stuff, Java introduced the SecurityManager. Before some action was performed, the SecurityManager was asked if the code is privileged to perform this action. However, since the SecurityManager lives in the same running program and can be accessed via System.getSecurityManager(), there existed some ways to remove it. Continue reading “Java Buffer Overflow with ByteBuffer (CVE-2020-2803) and Mutable MethodType (CVE-2020-2805) Sandbox Escapes”Continue reading
Recently, I discovered a sandbox breakout in the Groovy Sandbox used by the Jenkins script-security Plugin in their Pipeline Plugin for build scripts. We responsibly disclosed this vulnerability and in the current version of Jenkins it has been fixed and the according Jenkins Security Advisory 2019-09-12 has been published. In this blogpost I want to report a bit on the technical details of the vulnerability.Continue reading
While waiting for a download to complete, I stumbled across an interesting blogpost. The author describes a flaw in LibreOffice that allowed an attacker to execute code. Since this was quite recent, I was interested if my version is vulnerable to this attack and how they fixed it. Thus, I looked at the sources and luckily it was fixed. What I didn’t know before however was, that macros shipped with LibreOffice are executed without prompting the user, even on the highest macro security setting. So, if there would be a system macro from LibreOffice with a bug that allows to execute code, the user would not even get a prompt and the code would be executed right away. Therefor, I started to have a closer look at the source code and found out that exactly this is the case!