/tags/linux/ Recent content in Linux on unixawy.com | Security Blog Hugo en-us Thu, 14 Jul 2016 16:08:25 +0000 /iptables-prerouting-postrouting/ Thu, 14 Jul 2016 16:08:25 +0000 /iptables-prerouting-postrouting/ A guide to implementing complex traffic redirection and routing across multi-homed Linux servers using Netfilter PREROUTING (DNAT) and POSTROUTING (SNAT/MASQUERADE). /docker-crash-course/ Mon, 30 May 2016 03:00:06 +0000 /docker-crash-course/ A comprehensive guide to Docker core concepts, daemon architecture, interactive vs. detached modes, port mapping, and image customization. /audit-keystrokes-with-pam/ Wed, 07 Oct 2015 22:36:23 +0000 /audit-keystrokes-with-pam/ How to capture and audit real-time interactive TTY keystrokes in Linux using the pam_tty_audit module and aureport, preventing bash history tampering. /protect-bootsingle-user-mode/ Mon, 17 Aug 2015 03:42:42 +0000 /protect-bootsingle-user-mode/ How to prevent unauthorized local console takeovers on Linux by password-protecting GRUB, enforcing sulogin on single-user recovery mode, and disabling console reboot interrupts. /securelock-accounts-with-pam-tally2/ Wed, 05 Aug 2015 00:50:28 +0000 /securelock-accounts-with-pam-tally2/ How to configure PAM to automatically lock accounts after repeated failed login attempts across SSH, consoles, and TTYs using pam_tally2. /password-policy-with-pam_cracklib/ Mon, 03 Aug 2015 18:33:37 +0000 /password-policy-with-pam_cracklib/ A practical guide to enforcing strict password complexity, dictionary checks, and immediate expiration across Linux accounts using pam_cracklib. /pluggable-authentication-modules/ Mon, 03 Aug 2015 16:51:56 +0000 /pluggable-authentication-modules/ A comprehensive guide to Linux Pluggable Authentication Modules (PAM): management groups, control flags, module stacks, and configuration architecture. /find-duplicated-uid-in-the-linux-system/ Thu, 16 Jul 2015 02:03:09 +0000 /find-duplicated-uid-in-the-linux-system/ How to audit Linux passwd databases for duplicate UIDs—a common indicator of backdoor accounts and local privilege abuse. /users-in-shadow-file-explanation/ Thu, 16 Jul 2015 01:09:24 +0000 /users-in-shadow-file-explanation/ A detailed breakdown of the 9 fields in the Linux /etc/shadow file, password hash algorithms ($1, $5, $6), epoch timestamp math, and account aging with chage. /aide-intrusion-detection-environment/ Tue, 14 Jul 2015 05:05:05 +0000 /aide-intrusion-detection-environment/ How to configure Advanced Intrusion Detection Environment (AIDE) on Linux to detect unauthorized file tampering, privilege escalations, ACL changes, and rootkits. /umask-permissions-explanation/ Fri, 10 Jul 2015 07:16:00 +0000 /umask-permissions-explanation/ How the Linux umask (user mask) controls default permissions on newly created files and directories, binary bitmask calculation, and security hardening. /removable-disk-could-lead-to-privilege-escalation/ Sun, 05 Jul 2015 22:41:43 +0000 /removable-disk-could-lead-to-privilege-escalation/ How auto-mounted removable USB drives and external filesystems without nosuid and noexec mount options allow local privilege escalation on Linux systems. /persistent-mount-for-luks-with-unlock-key/ Sun, 05 Jul 2015 04:18:13 +0000 /persistent-mount-for-luks-with-unlock-key/ How to configure automated headless unlocking and persistent mounting for LUKS block devices on system boot using keyfiles, /etc/crypttab, and /etc/fstab. /linux-disk-encryption-with-luks/ Sun, 05 Jul 2015 02:50:28 +0000 /linux-disk-encryption-with-luks/ A complete step-by-step walkthrough of formatting, unlocking, mounting, and securing encrypted Linux block partitions using cryptsetup and LUKS. /iptables-redirect-ports-one-port/ Thu, 08 Jan 2015 21:27:08 +0000 /iptables-redirect-ports-one-port/ How to use Linux Netfilter iptables PREROUTING rules with DNAT to redirect broad port ranges or all incoming TCP traffic to a single destination port. /get-environment-variable-memory-address/ Thu, 04 Dec 2014 19:32:27 +0000 /get-environment-variable-memory-address/ How to reliably determine the memory address of environment variables on the Linux stack during binary exploitation and ret2env attacks. /files-encrypt-with-gpg/ Mon, 24 Nov 2014 15:20:24 +0000 /files-encrypt-with-gpg/ A quick practical guide to symmetric and asymmetric file encryption using GnuPG (GPG) for secure transmission and storage in Linux.