{"id":5665,"date":"2023-02-16T14:04:14","date_gmt":"2023-02-16T08:34:14","guid":{"rendered":"https:\/\/trysiteprice.com\/blog\/?p=5665"},"modified":"2023-02-16T14:04:14","modified_gmt":"2023-02-16T08:34:14","slug":"linux-kernel-etc-sysctl-conf-security-hardening","status":"publish","type":"post","link":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/","title":{"rendered":"Linux Kernel \/etc\/sysctl.conf Security Hardening"},"content":{"rendered":"

The \/etc\/sysctl.conf<\/code> file is used to configure various system parameters on Linux systems, including security-related settings. Here are some steps you can take to harden your Linux kernel by editing the \/etc\/sysctl.conf<\/code> file:<\/p>\n

    \n
  1. Open the \/etc\/sysctl.conf<\/code> file with your preferred text editor.<\/li>\n<\/ol>\n
    \n
    <\/div>\n
    sudo nano \/etc\/sysctl.conf
    \n<\/code><\/div>\n<\/div>\n
      \n
    1. Set the following parameters to restrict access to the \/proc<\/code> filesystem:<\/li>\n<\/ol>\n
      \n
      <\/div>\n
      kernel.dmesg_restrict = 1
      \nkernel.kptr_restrict = 2
      \n<\/code><\/div>\n<\/div>\n

      The kernel.dmesg_restrict<\/code> parameter restricts access to the kernel message buffer, and the kernel.kptr_restrict<\/code> parameter prevents the kernel’s internal pointers from being exposed to non-privileged users.<\/p>\n

        \n
      1. Set the following parameters to prevent IP spoofing and to enable TCP SYN cookies:<\/li>\n<\/ol>\n
        \n
        <\/div>\n
        net.ipv4.conf.all<\/span>.rp_filter = 1<\/span>
        \nnet.ipv4.conf.default.rp_filter = 1<\/span>
        \nnet.ipv4.tcp_syncookies = 1<\/span>
        \n<\/code><\/div>\n<\/div>\n

        The net.ipv4.conf.all.rp_filter<\/code> and net.ipv4.conf.default.rp_filter<\/code> parameters enable reverse path filtering, which helps prevent IP spoofing. The net.ipv4.tcp_syncookies<\/code> parameter enables TCP SYN cookies, which can help prevent certain types of denial-of-service attacks.<\/p>\n

          \n
        1. Set the following parameters to limit the number of concurrent connections and to prevent SYN flooding:<\/li>\n<\/ol>\n
          \n
          <\/div>\n
          net.ipv4.tcp_max_syn_backlog<\/span> =<\/span> 2048<\/span>
          \nnet.ipv4.tcp_synack_retries<\/span> =<\/span> 2<\/span>
          \nnet.ipv4.tcp_syn_retries<\/span> =<\/span> 5<\/span>
          \nnet.ipv4.tcp_tw_recycle<\/span> =<\/span> 1<\/span>
          \nnet.ipv4.tcp_tw_reuse<\/span> =<\/span> 1<\/span>
          \n<\/code><\/div>\n<\/div>\n

          The net.ipv4.tcp_max_syn_backlog<\/code> parameter limits the number of outstanding SYN requests that can be pending at any given time. The net.ipv4.tcp_synack_retries<\/code> and net.ipv4.tcp_syn_retries<\/code> parameters limit the number of times a TCP connection request can be retried. The net.ipv4.tcp_tw_recycle<\/code> and net.ipv4.tcp_tw_reuse<\/code> parameters allow the reuse of TIME_WAIT sockets to prevent SYN flooding.<\/p>\n

            \n
          1. Save and close the file.<\/li>\n
          2. Apply the new settings by running the following command:<\/li>\n<\/ol>\n
            \n
            <\/div>\n
            sudo sysctl -p<\/span>
            \n<\/code><\/div>\n<\/div>\n

            These are just a few examples of the many parameters you can set in the \/etc\/sysctl.conf<\/code> file to harden your Linux kernel. Be sure to read the documentation and choose the parameters that are appropriate for your system and use case.<\/p>\n","protected":false},"excerpt":{"rendered":"

            The \/etc\/sysctl.conf file is used to configure various system parameters on Linux systems, including security-related settings. Here are some steps you can take to harden your Linux kernel by editing the \/etc\/sysctl.conf file: Open the \/etc\/sysctl.conf file with your preferred text editor. sudo nano \/etc\/sysctl.conf Set the following parameters to restrict access to the \/proc … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-5665","post","type-post","status-publish","format-standard","hentry","category-best-tutorial"],"yoast_head":"\nLinux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice<\/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:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Linux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice\" \/>\n<meta property=\"og:description\" content=\"The \/etc\/sysctl.conf file is used to configure various system parameters on Linux systems, including security-related settings. Here are some steps you can take to harden your Linux kernel by editing the \/etc\/sysctl.conf file: Open the \/etc\/sysctl.conf file with your preferred text editor. sudo nano \/etc\/sysctl.conf Set the following parameters to restrict access to the \/proc ... Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\" \/>\n<meta property=\"og:site_name\" content=\"TrySitePrice\" \/>\n<meta property=\"article:published_time\" content=\"2023-02-16T08:34:14+00:00\" \/>\n<meta name=\"author\" content=\"Rahul Sahu\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\"},\"author\":{\"name\":\"Rahul Sahu\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/358e04eeea4281deacad2f30c58e67f4\"},\"headline\":\"Linux Kernel \/etc\/sysctl.conf Security Hardening\",\"datePublished\":\"2023-02-16T08:34:14+00:00\",\"dateModified\":\"2023-02-16T08:34:14+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\"},\"wordCount\":236,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/#organization\"},\"articleSection\":[\"Best\/Tutorial\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\",\"url\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\",\"name\":\"Linux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice\",\"isPartOf\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/#website\"},\"datePublished\":\"2023-02-16T08:34:14+00:00\",\"dateModified\":\"2023-02-16T08:34:14+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/trysiteprice.com\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Linux Kernel \/etc\/sysctl.conf Security Hardening\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#website\",\"url\":\"https:\/\/trysiteprice.com\/blog\/\",\"name\":\"TrySitePrice\",\"description\":\"Free Website Value Calculator Tool\",\"publisher\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/trysiteprice.com\/blog\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#organization\",\"name\":\"TrySitePrice\",\"url\":\"https:\/\/trysiteprice.com\/blog\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/trysiteprice.com\/blog\/wp-content\/uploads\/2021\/12\/cropped-trysiteprice-logo.png\",\"contentUrl\":\"https:\/\/trysiteprice.com\/blog\/wp-content\/uploads\/2021\/12\/cropped-trysiteprice-logo.png\",\"width\":395,\"height\":268,\"caption\":\"TrySitePrice\"},\"image\":{\"@id\":\"https:\/\/trysiteprice.com\/blog\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/358e04eeea4281deacad2f30c58e67f4\",\"name\":\"Rahul Sahu\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/51f0f95f7b95665f62baed2211572165?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/51f0f95f7b95665f62baed2211572165?s=96&d=mm&r=g\",\"caption\":\"Rahul Sahu\"},\"sameAs\":[\"https:\/\/trysiteprice.com\/blog\"],\"url\":\"https:\/\/trysiteprice.com\/blog\/author\/rsahu4242_trysiteprice\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Linux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice","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:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/","og_locale":"en_US","og_type":"article","og_title":"Linux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice","og_description":"The \/etc\/sysctl.conf file is used to configure various system parameters on Linux systems, including security-related settings. Here are some steps you can take to harden your Linux kernel by editing the \/etc\/sysctl.conf file: Open the \/etc\/sysctl.conf file with your preferred text editor. sudo nano \/etc\/sysctl.conf Set the following parameters to restrict access to the \/proc ... Read more","og_url":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/","og_site_name":"TrySitePrice","article_published_time":"2023-02-16T08:34:14+00:00","author":"Rahul Sahu","twitter_card":"summary_large_image","schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#article","isPartOf":{"@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/"},"author":{"name":"Rahul Sahu","@id":"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/358e04eeea4281deacad2f30c58e67f4"},"headline":"Linux Kernel \/etc\/sysctl.conf Security Hardening","datePublished":"2023-02-16T08:34:14+00:00","dateModified":"2023-02-16T08:34:14+00:00","mainEntityOfPage":{"@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/"},"wordCount":236,"commentCount":0,"publisher":{"@id":"https:\/\/trysiteprice.com\/blog\/#organization"},"articleSection":["Best\/Tutorial"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/","url":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/","name":"Linux Kernel \/etc\/sysctl.conf Security Hardening - TrySitePrice","isPartOf":{"@id":"https:\/\/trysiteprice.com\/blog\/#website"},"datePublished":"2023-02-16T08:34:14+00:00","dateModified":"2023-02-16T08:34:14+00:00","breadcrumb":{"@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/trysiteprice.com\/blog\/linux-kernel-etc-sysctl-conf-security-hardening\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/trysiteprice.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Linux Kernel \/etc\/sysctl.conf Security Hardening"}]},{"@type":"WebSite","@id":"https:\/\/trysiteprice.com\/blog\/#website","url":"https:\/\/trysiteprice.com\/blog\/","name":"TrySitePrice","description":"Free Website Value Calculator Tool","publisher":{"@id":"https:\/\/trysiteprice.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/trysiteprice.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/trysiteprice.com\/blog\/#organization","name":"TrySitePrice","url":"https:\/\/trysiteprice.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/trysiteprice.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/trysiteprice.com\/blog\/wp-content\/uploads\/2021\/12\/cropped-trysiteprice-logo.png","contentUrl":"https:\/\/trysiteprice.com\/blog\/wp-content\/uploads\/2021\/12\/cropped-trysiteprice-logo.png","width":395,"height":268,"caption":"TrySitePrice"},"image":{"@id":"https:\/\/trysiteprice.com\/blog\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/358e04eeea4281deacad2f30c58e67f4","name":"Rahul Sahu","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/trysiteprice.com\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/51f0f95f7b95665f62baed2211572165?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/51f0f95f7b95665f62baed2211572165?s=96&d=mm&r=g","caption":"Rahul Sahu"},"sameAs":["https:\/\/trysiteprice.com\/blog"],"url":"https:\/\/trysiteprice.com\/blog\/author\/rsahu4242_trysiteprice\/"}]}},"_links":{"self":[{"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/posts\/5665","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/comments?post=5665"}],"version-history":[{"count":1,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/posts\/5665\/revisions"}],"predecessor-version":[{"id":5668,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/posts\/5665\/revisions\/5668"}],"wp:attachment":[{"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/media?parent=5665"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/categories?post=5665"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/trysiteprice.com\/blog\/wp-json\/wp\/v2\/tags?post=5665"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}