-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= pfSense-SA-19_03.webgui Security Advisory pfSense Topic: XSS vulnerability in the WebGUI Category: pfSense Base System Module: webgui Announced: 2019-05-20 Credits: Dharmesh Baskaran -- https://www.linkedin.com/in/dharmeshbaskaran CVE ID: CVE-2020-19201 Affects: pfSense software versions <= 2.4.4-p2 Corrected: 2019-05-03 19:24:43 UTC (pfSense/master, pfSense 2.5.0) 2019-05-03 19:24:43 UTC (pfSense/RELENG_2_4_4, pfSense 2.4.4-pX) 0. Revision History v1.1 2021-05-20 Added CVE ID v1.0 2019-05-20 Initial SA draft I. Background pfSense® software is a free network firewall distribution based on the FreeBSD operating system. The pfSense software distribution includes third- party free software packages for additional functionality, and provides most of the functionality of common commercial firewalls. The majority of users of pfSense software have never installed or used a stock FreeBSD system. Unlike similar GNU/Linux-based firewall distributions, there is no need for any UNIX knowledge. The command line is never used, and there is no need to ever manually edit any rule sets. Instead, pfSense software includes a web interface for the configuration of all included components. Users familiar with commercial firewalls will quickly understand the web interface, while those unfamiliar with commercial-grade firewalls may encounter a short learning curve. II. Problem Description A Cross-Site Scripting (XSS) vulnerability was found in status_filter_reload.php, a page in the pfSense software WebGUI, on version 2.4.4-p2 and earlier. The page did not encode output from the filter reload process, and a stored XSS was possible via the descr (description) parameter on NAT rules. III. Impact Due to the lack of proper encoding on the affected parameters susceptible to XSS, arbitrary JavaScript could be executed in the user's browser. The user's session cookie or other information from the session may be compromised. IV. Workaround No workaround. To help mitigate the problem on older releases, use one or more of the following: * Do not give firewall administrators access to pages or functions which allow writing arbitrary files to the firewall. * Limit access to the affected pages to trusted administrators only. * Do not log into the firewall with the same browser used for non- administrative web browsing. V. Solution Users can upgrade to version 2.4.4-p3 or later. This upgrade may be performed in the web interface or from the console. See https://docs.netgate.com/pfsense/en/latest/install/upgrade-guide.html Users may also apply the relevant revisions below using the System Patches package to obtain the fix. See https://docs.netgate.com/pfsense/en/latest/development/system-patches.html VI. Correction details The following list contains the correction revision commit ID for each affected item. Branch/path Revision - - ------------------------------------------------------------------------- pfSense/master 1af9400d594cd183d011f22fa9b3a7630570a250 pfSense/RELENG_2_4_4 41c9fac85c3ff621665bd7fa7b9af497bc16fd3a - - ------------------------------------------------------------------------- VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE40XvjEU56XSUPIMdE7mH/ZIU+NoFAmCmwfwACgkQE7mH/ZIU +NoBMBAAhXISdoPKfTHNBc3O1ww9Zrm2mHtI3OkAD9bkM/iSAJSeQFQlI4UD9iop qrJyEyg7mMv9fovzHK2Gt8OHD6KpAR4BDg1wY9OncCgjpq4Yb6AMtqQuDaR0JPnZ ViLK+UxbLnQd3zNPnzBdm1t5BduBcrtt0b0HJFqjWSknm5rV9Zq33W2TCXmHezUv MmlBL9WdWizw6n+Z00sgy7gdScglu2yFYr4trEXz1PwAOqZGsPTtW4s/BzLL72jZ PtZr8kWA30y/4sWT0EM4A46aeDVEPXekGjJOJGDhHT+qP4eu38urcm4SqElzhtdI UqgQCmlU4Vzv4jz0LxvJL9eTGLlDzJLfX0iaCyrdDrPixXR1PRk0alyFT6dB95yk G4qCVw+KA3uBgBDVSU4TmdEnCQoqjGhgEmcWc5PxAxR4FRmmT5cqJgYPuaT5vIyZ N3iLWpPr4UdAjJhBYKNHGUw1BuPSX4i4DJyS2vA72gh9WGnEGxtNGTJK5O0ugX/1 nLBslRiRHDCdyePhcjjtfY9ROQinF4Z7m+Bqp0cvwrgWgDBZBMaGE6osP4GMPqm+ kbO2EJXGNIEyc5+kNzo1//PSM+9DokKYI7kgyBnUHfKHuvh8vLpiGUujLd129cUt 77j0tujnyuApe2gBp0uliBAJwC8ciuSIl0WtQKJI2dpurCR85PE= =tEfW -----END PGP SIGNATURE-----