The OpenSSL Memory Leak With No CVE to Patch Against
Okta's Red Team gave this one a name, HollowByte, and named things get attention. What deserves the attention here isn't the trick — it's the paperwork, or rather the lack of it.
4 min read
Ketan AagjaDirector of IT · 22+ years in infrastructure, security & mail systems
Runs enterprise networks and security for a living, and writes Shore Up to turn two decades of hands-on Linux, Windows and mail-server work into guides you can actually use.
Configure High Availability on a SonicWall Pair
This guide pairs two identical SonicWall appliances into an Active/Standby High Availability cluster: the Primary handles all traffic, the Secondary sits synchronized and idle, and if the Primary fails the Secondary takes over the firewall's identity and keeps traffic flowing. That is the whole purpose — surviving a hardware failure without hand-rebuilding a box.
6 min read
Automate DNS Record Audits on Windows DNS with PowerShell
This guide builds a read-only audit of a Microsoft DNS server: it enumerates the zones, exports every resource record to CSV, and produces a short report of records that look stale (dynamic records whose aging timestamp is older than a threshold you set). The audit script itself creates nothing and deletes nothing — its worst case is a CSV file on disk.
9 min read
Automate Container Image Cleanup on a Docker Host
Docker hosts fill up quietly. Every docker pull , every CI build, every image rebuild leaves layers behind, and /var/lib/docker grows until a deploy fails with "no space left on device" at the worst possible moment. This guide sets up a scheduled job that prunes unused images older than a threshold you choose, so the host reclaims space on its own without you babysitting it.
9 min read
Back Up and Restore SonicWall Settings and Firmware Safely
This guide covers two related jobs on a SonicWall firewall: taking a full backup of the running configuration (and creating a restore point), and upgrading or rolling back firmware. The purpose is simple — never touch firmware or a risky rule change without a known-good copy you can boot back to.
6 min read
Generate a Disk-Space Report Across Servers with PowerShell Remoting
This guide builds a read-only disk-space report. It uses PowerShell remoting ( Invoke-Command over WinRM) to query each server's local fixed disks and returns size, free space, and percent free as one combined table you can export to CSV or HTML. It does not write to, resize, or clean up any disk — it only reads WMI/CIM data.
10 min read
Audit World-Writable Files and SUID Binaries with Bash
This script reads your filesystem and reports two classes of risky files: world-writable files and directories (anyone on the box can modify them) and SUID/SGID binaries (they run with the owner's or group's privileges, often root). It writes a timestamped report and, optionally, a baseline you can diff against later. It does not change any permissions, delete anything, or modify a single file — it only runs find and writes a text report to a directory you choose.
9 min read
The July kernel respin: reboot, and mind your out-of-tree modules
Canonical shipped a batch of Linux kernel security fixes this month, and LWN flagged three stable kernel updates landing upstream in the same window. None of this is dramatic. It is the ordinary heartbeat of running Linux under a mail stack — but "ordinary" still means a reboot, and there are two details worth reading before you schedule one.
3 min read
Set Up SSL VPN Remote Access on a SonicWall (NetExtender)
This guide configures SSL VPN (NetExtender) remote access on a SonicWall firewall: it opens an encrypted tunnel on the WAN so authorised users can dial in from the internet and reach an internal subnet. Everything here is done in the SonicOS web GUI as a full administrator account — there is no "script" to paste, but the changes are just as production-critical as one.
7 min read
Automate User Offboarding in Active Directory with PowerShell
This script offboards one leaving user in a single pass: it disables their AD account, records and removes their group memberships (except the primary group), and moves the account into a disabled-users OU. A separate, clearly marked step sets mail forwarding on their mailbox. The point is a consistent, logged procedure so nothing gets missed and you can reconstruct exactly what changed.
9 min read
Automate iptables/nftables Backup and Restore
This guide sets up two things: a small script that dumps your host's live packet-filter ruleset to a timestamped, versioned file, and a scheduled systemd timer to run it. It also shows the standard restore path. The backup part is read-only and safe. The restore part is not — reloading a ruleset replaces your firewall's entire running state in one transaction, and a bad ruleset can drop your SSH session and cut the host off the network instantly.
9 min read
Create Access Rules and NAT Policies on a SonicWall (SonicOS 7)
This guide walks through publishing one internal server to the Internet on a SonicWall running SonicOS 7 (7.0/7.1) — creating the address and service objects, an inbound NAT policy that translates your public IP to the server's private IP, and the access rule that permits the traffic. On a SonicWall the "script" is the vendor's own web GUI, so there is nothing to paste into a shell.
6 min read
Configure a Site-to-Site VPN on a SonicWall (SonicOS 7)
This guide builds an IPsec site-to-site VPN between two SonicWall firewalls (or a SonicWall and a compatible third-party peer) so two private subnets can route to each other over the public internet. It changes live firewall configuration: it adds a VPN policy, address objects, and — automatically — access rules that permit traffic between the two networks. Getting the phase 1/phase 2 parameters or the local/remote networks wrong can break routing or expose a subnet you didn't intend to.
6 min read