Security Research - IIS Short File/Folder Name Disclosure Website : http://soroush.secproject.com/blog/ I. BACKGROUND --------------------- "IIS is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows. IIS is the third most popular server in the world." (Wikipedia) II. DESCRIPTION --------------------- Vulnerability Research Team discovered a vulnerability in Microsoft IIS. The vulnerability is caused by a tilde character "~" in a Get request, which could allow remote attackers to diclose File and Folder names. III. AFFECTED PRODUCTS --------------------------- IIS 1.0, Windows NT 3.51 IIS 2.0, Windows NT 4.0 IIS 3.0, Windows NT 4.0 Service Pack 2 IIS 4.0, Windows NT 4.0 Option Pack IIS 5.0, Windows 2000 IIS 5.1, Windows XP Professional and Windows XP Media Center Edition IIS 6.0, Windows Server 2003 and Windows XP Professional x64 Edition IIS 7.0, Windows Server 2008 and Windows Vista IIS 7.5, Windows 7 (error remotely enabled or no web.config) IIS 7.5, Windows 2008 (classic pipeline mode) Note: Does not work when IIS uses .Net Framework 4. IV. Binary Analysis & Exploits/PoCs --------------------------------------- Tilde character "~" can be used to find short names of files and folders when the website is running on IIS. The attacker can find important file and folders that they are not normaly visible. In-depth technical analysis of the vulnerability and a functional exploit are available through: http://soroush.secproject.com/blog/2012/06/microsoft-iis-tilde-character-vulnerabilityfeature-short-filefolder-name-disclosure/ V. SOLUTION ---------------- There are still workarounds through Vendor and security vendors. Using a configured WAF may be usefull (discarding web requests including the tilde "~" character). VI. CREDIT -------------- This vulnerability was discovered by: Soroush Dalili (@irsdl) Ali Abbasnejad VII. REFERENCES ---------------------- http://support.microsoft.com/kb/142982/en-us http://soroush.secproject.com/blog/2010/07/iis5-1-directory-authentication-bypass-by-using-i30index_allocation/ VIII. DISCLOSURE TIMELINE ----------------------------- 2010-08-01 - Vulnerability Discovered 2010-08-03 - Vendor Informed 2010-12-01 - Vendor 1st Response 2011-01-04 - Vendor 2nd Response (next version fix) 2012-06-29 - Public Disclosure