A flaw has been discovered in the popular open-source browser Firefox that could expose sensitive information stored in memory, Secunia has warned.

Firefox versions 1.0.1 and 1.0.2 contain the vulnerability, the security information company said in an advisory on Monday. The flaw stems from an error in the JavaScript engine that can expose arbitrary amounts of heap memory after the end of a JavaScript string. As a result, an exploit may disclose sensitive information in the memory, Secunia said.