Several remote vulnerabilities have been discovered in Xulrunner, a runtime environment for XUL applications, such as the Iceweasel web browser. The Common Vulnerabilities and Exposures project identifies the following problems: Several issues in the browser engine have been discovered, which can result in the execution of arbitrary code. (MFSA 2009-24) It is possible to execute arbitrary code via vectors involving "double frame construction." (MFSA 2009-24) Jesse Ruderman and Adam Hauner discovered a problem in the JavaScript engine, which could lead to the execution of arbitrary code. (MFSA 2009-24) Pavel Cvrcek discovered a potential issue leading to a spoofing attack on the location bar related to certain invalid unicode characters. (MFSA 2009-25) Gregory Fleischer discovered that it is possible to read arbitrary cookies via a crafted HTML document. (MFSA 2009-26) Shuo Chen, Ziqing Mao, Yi-Min Wang and Ming Zhang reported a potential man-in-the-middle attack, when using a proxy due to insufficient checks on a certain proxy response. (MFSA 2009-27) Jakob Balle and Carsten Eiram reported a race condition in the NPObjWrapper_NewResolve function that can be used to execute arbitrary code. (MFSA 2009-28) moz_bug_r_a4 discovered that it is possible to execute arbitrary JavaScript with chrome privileges due to an error in the garbage-collection implementation. (MFSA 2009-29) Adam Barth and Collin Jackson reported a potential privilege escalation when loading a file::resource via the location bar. (MFSA 2009-30) Wladimir Palant discovered that it is possible to bypass access restrictions due to a lack of content policy check, when loading a script file into a XUL document. (MFSA 2009-31) moz_bug_r_a4 reported that it is possible for scripts from page content to run with elevated privileges and thus potentially executing arbitrary code with the object's chrome privileges. (MFSA 2009-32)