Posted on RISKS: ---------------------------------------------------------------------- Date: Fri, 22 Mar 1996 17:27:56 -0500 From: Ed Felten <felten@CS.Princeton.EDU> Subject: Java/Netscape security flaw We have discovered another serious security flaw in the Java programming language, which allows a malicious Java applet running under Netscape Navigator (version 2.0 or 2.01) to execute arbitrary machine code. We have implemented an applet that exploits the flaw to remove a file. Until a fix is issued, Netscape users can protect themselves by disabling Java in the Security Preferences dialog. At present we are not releasing technical details about the flaw. We will announce the full details later; some of the details will also appear in our upcoming paper in the proceedings of the IEEE Symposium on Security and Privacy, to be published in May. Our paper also contains an overall analysis of Java's security. For an advance copy of the paper, send mail to felten@cs.princeton.edu. The paper will be available in about a week. [Note that the "security enhancements" announced by Netscape in version 2.01 of Netscape Navigator do not fix this flaw. They fix two separate flaws found last month, one found by us (RISKS-17.77) and independently by Steve Gibbons, and the other found by David Hopwood (RISKS-17.83).] For more information, see http://www.cs.princeton.edu/~ddean/java, or contact Ed Felten at (609) 258-5906 or felten@cs.princeton.edu. Drew Dean, Ed Felten, Dan Wallach, Dept of Computer Science, Princeton Univ. [See the CIAC item at the end of this issue for some background on the earlier problems. PGN] ------------------------------ ------------------------------------------------------------------------- Steven Weller | Weller's three steps to Greatness: | 1. See what others cannot | 2. Think what others cannot stevenw@best.com | 3. Express what others cannot