XnView JLS File Decompression Heap Overflow Summary XnView Formats PlugIn is prone to an overflow condition. The JLS Plugin (xjpegls.dll) library fails to properly sanitize user-supplied input resulting in a heap-based buffer overflow. With a specially crafted JLS compressed image file, a context-dependent attacker could potentially execute arbitrary code. Advisory page: http://www.reactionpenetrationtesting.co.uk/xnview-jls-heap.html POC file posted at: http://www.reactionpenetrationtesting.co.uk/vuln.jls CVE number: CVE-2012-4988 Impact: High Vendor homepage: http://www.xnview.com/ Vendor notified: 29/06/2012 Vendor response: Fix was promised for 1.99.1 but no fix was released Found by: Joseph Sheridan, Director of Reaction Information Security About ReactionIS Reaction Information Security is a leading independent pen test consultancy specialising in delivering the highest quality services including network pen testing and web application security testing. As a CESG CHECK Service Provider we are authorised to carry out penetration testing on classified government networks. Affected Products XnView 1.99 and 1.99.1, 'All Plugins 1.90' and Xjpegls.dll (version 1.96.0.0) previous versions may also be affected. Details XnView Formats PlugIn is prone to an overflow condition. The JLS Plugin (xjpegls.dll) library fails to properly sanitize user-supplied input resulting in a heap-based buffer overflow. With a specially crafted JLS compressed image file, a context-dependent attacker could potentially execute arbitrary code. Impact If a user could be enticed to open a malicious JLS file, the attack could result in remote code execution. Solution No solution at the time of writing. Never open files from untrusted sources. Distribution In addition to posting on the website, a text version of this notice has been posted to the following e-mail and Usenet news recipients. bugtraq () securityfocus com full-disclosure () lists grok org uk Future updates of this advisory may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the advisory on our homepage at: http://www.reactionpenetrationtesting.co.uk/xnview-jls-heap.html Links: http://www.reactionpenetrationtesting.co.uk http://www.reactionpenetrationtesting.co.uk/security-whitepapers.html Joseph Sheridan Director CHECK Team Leader, CREST Infrastructure, CREST Application, CISSP Tel: 07812052515 Web: www.reactionis.co.uk Email: joe@reactionis.co.uk