{"id":77768,"date":"2020-01-22T16:42:00","date_gmt":"2020-01-22T11:12:00","guid":{"rendered":"https:\/\/www.vskills.in\/certification\/tutorial\/?p=77768"},"modified":"2024-04-12T14:29:55","modified_gmt":"2024-04-12T08:59:55","slug":"the-nasl-interpreter","status":"publish","type":"page","link":"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/","title":{"rendered":"The NASL Interpreter"},"content":{"rendered":"

The NASL Interpreter<\/strong><\/h4>\n

Use the NASL interpreter, nasl, to run and test NASL scripts via the command line. Invoke it with the -v flag to see what version is installed on your system:<\/p>\n[notroot]$ nasl -v<\/p>\n

nasl 2.0.10<\/p>\n

Copyright (C) 1999 – 2003 Renaud Deraison <deraison@cvs.nessus.org><\/p>\n

Copyright (C) 2002 – 2003 Michel Arboi <arboi@noos.fr><\/p>\n

See the license for details<\/p>\n

A vanilla Nessus installation comes packaged with NASL scripts that act as plug-ins for the Nessus scanner. The Nessus server executes these scripts to test for vulnerabilities, and you can find the scripts in the \/usr\/local\/lib\/ness\/plugins\/ directory. You can execute these scripts directly by invoking them with nasl. For example, the finger.nasl script checks to see if fingerd is enabled on a remote host. Finger is a service that listens on port 79 by default, and you can use it to query information about users. To run this script against a host with the IP address of 192.168.1.1 using the NASL interpreter, execute the following:<\/p>\n[notroot]$ nasl -t 192.168.1.1 finger.nasl<\/p>\n

** WARNING : packet forgery will not work<\/p>\n

** as NASL is not running as root<\/p>\n

The ‘finger’ service provides useful information to attackers, since it allows them to gain usernames, check if a machine is being used, and so on. Here is the output we obtained for ‘root’ :<\/p>\n

Login: root\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name: System Administrator<\/p>\n

Directory: \/var\/root\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Shell: \/bin\/sh<\/p>\n

On since Wed 5 May 08:51 (CDT) on ttyp2 from 127.0.0.1:0.0<\/p>\n

No Mail.<\/p>\n

No Plan.<\/p>\n

Solution : comment out the ‘finger’ line in \/etc\/inetd.conf<\/p>\n

Risk factor : Low<\/p>\n[6533] plug_set_key:send(0)[‘1 finger\/active=1;<\/p>\n

‘](0 out of 19): Socket operation on non-socket<\/p>\n

The preceding output is from the finger.nasl script, which was able to use the finger server running on host 192.168.1.1 to find out information about the root user.<\/p>\n

Apply for Network Security Open Source Software Developer Certification Now!!<\/h3>\n

https:\/\/www.vskills.in\/certification\/network-security-open-source-software-developer-certification<\/a><\/p>\n

Back to Tutorial<\/a><\/strong><\/h4>\n","protected":false},"excerpt":{"rendered":"

The NASL Interpreter Use the NASL interpreter, nasl, to run and test NASL scripts via the command line. Invoke it with the -v flag to see what version is installed on your system: [notroot]$ nasl -v nasl 2.0.10 Copyright (C) 1999 – 2003 Renaud Deraison <deraison@cvs.nessus.org> Copyright (C) 2002 – 2003 Michel Arboi <arboi@noos.fr> See…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"categories":[9066],"tags":[9071],"class_list":["post-77768","page","type-page","status-publish","hentry","category-network-security-open-source","tag-the-nasl-interpreter"],"acf":[],"yoast_head":"\nThe NASL Interpreter - Tutorial<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The NASL Interpreter - Tutorial\" \/>\n<meta property=\"og:description\" content=\"The NASL Interpreter Use the NASL interpreter, nasl, to run and test NASL scripts via the command line. Invoke it with the -v flag to see what version is installed on your system: [notroot]$ nasl -v nasl 2.0.10 Copyright (C) 1999 – 2003 Renaud Deraison <deraison@cvs.nessus.org> Copyright (C) 2002 – 2003 Michel Arboi <arboi@noos.fr> See...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/\" \/>\n<meta property=\"og:site_name\" content=\"Tutorial\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/vskills.in\/\" \/>\n<meta property=\"article:modified_time\" content=\"2024-04-12T08:59:55+00:00\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/\",\"url\":\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/\",\"name\":\"The NASL Interpreter - Tutorial\",\"isPartOf\":{\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#website\"},\"datePublished\":\"2020-01-22T11:12:00+00:00\",\"dateModified\":\"2024-04-12T08:59:55+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.vskills.in\/certification\/tutorial\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"The NASL Interpreter\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#website\",\"url\":\"https:\/\/www.vskills.in\/certification\/tutorial\/\",\"name\":\"Tutorial\",\"description\":\"Vskills - A initiative in elearning and certification\",\"publisher\":{\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.vskills.in\/certification\/tutorial\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#organization\",\"name\":\"Vskills\",\"url\":\"https:\/\/www.vskills.in\/certification\/tutorial\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.vskills.in\/certification\/tutorial\/wp-content\/uploads\/2017\/07\/vskills-min-logo.jpg\",\"contentUrl\":\"https:\/\/www.vskills.in\/certification\/tutorial\/wp-content\/uploads\/2017\/07\/vskills-min-logo.jpg\",\"width\":73,\"height\":55,\"caption\":\"Vskills\"},\"image\":{\"@id\":\"https:\/\/www.vskills.in\/certification\/tutorial\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/vskills.in\/\",\"https:\/\/x.com\/vskills_in\",\"https:\/\/www.linkedin.com\/company-beta\/1371554\/\",\"https:\/\/www.youtube.com\/channel\/UCMWnscxPwRF_PqXo9B7q_Tw\"]}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"The NASL Interpreter - Tutorial","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.vskills.in\/certification\/tutorial\/the-nasl-interpreter\/","og_locale":"en_US","og_type":"article","og_title":"The NASL Interpreter - Tutorial","og_description":"The NASL Interpreter Use the NASL interpreter, nasl, to run and test NASL scripts via the command line. 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