#Audit
Cross-Model Audits of AI-Written Code — Process, Not Faith
After using AI to port a calculator from a 35-sheet engineering spreadsheet, how do I know it is correct? This article covers three independent audit rounds by an agent from another provider, the rules to set before starting, confidence levels that keep claims within the evidence, and the classes of errors AI kept making in every round.
Migrating an Old .aspx Site to a JSON Catalog and Filtering Images
The owner of an old .aspx site asked me to rebuild it, but more than a decade of content was in a database I could no longer access. I collected the pages from the site itself to build a JSON catalog that preserved every legacy_id, then wrote a three-layer image filter to keep stray QR codes from becoming article covers.
Reverse Engineering Spreadsheet Constants into Formulas
A sheet has a criteria table sitting beside the calculations, but no VLOOKUP connects them. People read the table and type values into cells themselves, and mistakes go unnoticed. This article covers separating formula cells from manually entered cells, then reconstructing a single formula that matches all 16 values in a multiplier column.
A Blank Page with No Errors, All Because I Named a Function top
After deployment, the page was blank, the logs had no errors, and node --check found nothing wrong. But the browser stopped the entire script before the first line ran because a function named top collided with window.top. Here are the names to avoid, the script loading order trap, and the Playwright check every project should have.
Cannot Delete Faces from a Terminal: API Returns notSupport
The door's face recognition terminal advertises a command to delete faces from FDLib, but every variation I tried returned notSupport. People who had left could still scan their faces and get in. This article covers the dead ends, the approach that actually worked using UserInfo/Modify with the smallest possible body, and the two-way user registry sync that runs every night.
Writing to DirectAdmin Through Panel Forms When the API Only Reads
Notes on letting a back-office app create and edit hosting packages in DirectAdmin when the official CMD_API only provides read operations, requiring POST requests directly to control panel forms, with verification rules that prohibit regex and two layers of kill switches disabled by default.
Registrar and Billing NS Mismatch: Audit All Three Sides First
A debugging log for "Wrong response from the server" when changing nameservers in a billing system, which failed only for domains with leftover glue IP data, followed by a three-way audit of the registrar, billing system, and actual DNS zones before I felt confident changing anything.
Let AI Read Documents, but Let Code Do the Math
The controller requires manually entered values to fall between 0 and 100, but the path where AI reads values from documents and feeds them in only checks whether they are numeric. A single negative value inflated the result to 5.25 times what it should have been without an error — a lesson in treating AI output as untrusted input, just like values entered by people.
Secrets Set to 600, but 0644 Logs Go Offsite Every Night
The .env is encrypted and permissions are locked down on every secret file, but customer data still leaks off the machine every night through something nobody classifies as confidential: logs that every account on the machine can read, bundled into backups uploaded to object storage. Here is how I stop it at the source by logging only result codes.
Mailbox Compromised or Just Password Guessing? Prove It First
Telling a customer their account has been compromised is an allegation that needs decisive evidence first. This article covers what counts as decisive evidence, two cases with opposite outcomes, and the case I nearly reported incorrectly.
Using an NVR to Reach Inaccessible Cameras with ISAPI and SDK
The cameras sit behind the NVR's second interface, and none are directly reachable. This article works through what the NVR's ISAPI can actually do, with 26 of 38 tested endpoints working, retrieves CCTV snapshots and RTSP through the NVR, finds when each channel last recorded, and falls back to HCNetSDK through ctypes to read device logs when ISAPI runs out of options.
Auditing prod with real customer data without leaving a single row
The system owner asked me to test the entire system on the live server holding customer data without leaving even a single junk row behind. My approach was to bootstrap Laravel myself and call controllers directly inside a transaction that I rolled back, with a COUNT of every table before and after as evidence.
Auditing CCTV Directly with ISAPI and ffprobe RTSP, Bypassing the NVR
The NVR screen only tells you a camera is online. It does not tell you its model, how old its firmware is, or the actual stream resolution. In this article, I write a script to query ISAPI deviceInfo on each camera directly, then use ffprobe to read values from the actual RTSP stream to build an inventory and check the health of the camera system I maintain.
Inventory Switch and AP Ports with SNMP Walk and MAC Tables
You can build your own Layer 2 inventory without a controller or NMS. Write an SNMP walk with pysnmp asyncio to retrieve sysDescr, ifTable, and the bridge FDB, then convert OID indexes back into MAC addresses to find which device connects to which port on which switch.
Screenshot Multiple Domains Directly from Origin, Bypassing Cloudflare
Need screenshots of dozens of domains for inspection, or want to confirm that the origin server (not the CDN cache) renders correctly — but Chrome's screenshot flag has been broken since version 132, and AV reverts hosts edits? This article uses Playwright to override DNS at the process level, solving both problems.
nginx heap overflow spans 15 years—version checks aren't enough
CVE-2026-42533 affects nginx versions 0.9.6 through 1.31.2, spanning 15 years, but actual exposure depends on the config, not the version. The problem is that news reports describe narrower conditions than the real ones. Checking against those reports can return "safe" even when the config still meets the conditions.
Read-only Debian shared-host security audit — avoid banning yourself
Audit the security of a Debian server running DirectAdmin in read-only mode first — but the first trap is that scan traffic itself triggers CSF's brute-force rules and gets your own IP banned. This article lays out a safe audit sequence + areas to check in 2024-2026