SURbit Posted February 10, 2016 Share Posted February 10, 2016 Older versions of the Java installer were vulnerable to binary planting in the Downloads folder On most computers, the default download folder quickly becomes a repository of old and unorganized files that were opened once and then forgotten about. A recently fixed flaw in the Java installer highlights why keeping this folder clean is important. On Friday, Oracle published a security advisory recommending that users delete all the Java installers they might have laying around on their computers and use new ones for versions 6u113, 7u97, 8u73 or later. The reason is that older Java installers are designed to look for and automatically load a number of specifically named DLL (Dynamic Link Library) files from the current directory. In the case of Java installers downloaded from the Web, the current directory is typically the computer's default download folder. If an attacker manages to place a specifically named malicious DLL into a computer's "Downloads" folder, that file will be executed when the user tries to install Java for the first time or when he manually updates an existing Java installation by downloading and running a new installer. "Though considered relatively complex to exploit, this vulnerability may result, if successfully exploited, in a complete compromise of the unsuspecting user’s system," said Eric Maurice, Oracle's software security assurance director, in a blog post. This attack technique is called binary planting and has been known for a while. Over the past several years many software installers have been found to be vulnerable to it. "If you launch Process Monitor and observe activities in the Downloads folder when any installer is launched, you will find a long series of attempts to load various DLLs," researchers from Acros Security said in a blog post back in Feb. 2012. "Not surprising: this is how library loading works (first trying to find DLLs in the same folder as EXE), and in most cases it would not be a security problem as most folders hosting your EXEs are not attacker-writable. However, the Downloads folder is -- to some extent, anyway." Some browsers are configured to automatically download files, even if they don't execute them. Furthermore, clearing the download list from browsers only empties the download history. It does not actually remove the downloaded files. It's not hard to imagine a sort of carpet bombing attack where a malicious or infected website drops specifically named DLL files on users' computers on the chance that a small percentage of them will later be executed by vulnerable installers. To avoid something like this users should regularly clean the Downloads folder themselves. SOURCE Link to comment Share on other sites More sharing options...
Administrator DKT27 Posted February 10, 2016 Administrator Share Posted February 10, 2016 Found out some time ago I had huge collection of those Java installers. Deleted them. This why installers should stick to one single name rather than version number in the file name, higher chances of overwriting the previous installer I think. Link to comment Share on other sites More sharing options...
VileTouch Posted February 10, 2016 Share Posted February 10, 2016 i don´t think this applies to the download folder as much as it applies to the TEMP folder. when the browser prompts you if you want to run the installer instead of downloading it (internet explorer) it is downloaded to the TEMP folder where any number of dlls from previous installed programs could reside. this is more of a threat because all installers have access to this folder and it´s up to the developer to clean up after themselves, NOT the os. besides. loading dlls by calling them and catching the exception is sloppy coding. first you enumerate the current directory in one operation and buffer the results, then evaluate in memory if there´s any match, then read the signatures to ensure this is indeed a legit library AND THEN you attempt to call it. it´s amazing howw big companies act like script kiddies Link to comment Share on other sites More sharing options...
Escritoire Posted February 10, 2016 Share Posted February 10, 2016 11 hours ago, SURbit said: Older versions of the Java installer were vulnerable to binary planting in the Downloads folder ... For years, I use JavaRA (Now release 2.6.1) to cope with this. Install, update, remove and clean Java with this welcome and precious freeware. The site: https://singularlabs.com/software/javara/ Regards. Link to comment Share on other sites More sharing options...
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