Elevate the standalone before it unpacks, into a locked directory - #50
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The standalone extracted its payload to a per-user %TEMP% directory and ran Winnow.ps1 from there as the unelevated user; Winnow then self-elevated via RunAs. That means the elevated run dot-sourced its ~100 scripts from a directory the standard user still controls, so a local user could swap one of those files between extraction and execution and have it run with the elevated process's rights. Local privilege escalation. Flip the order: check for admin at the top, relaunch the standalone itself through RunAs if needed, and only extract once elevated. Extract into a fresh directory locked to Administrators and SYSTEM with inheritance off, so the user cannot write to it even though it sits under their %TEMP%. Switched the directory name from an 8-char guid fragment to a full guid. Added Test-StandaloneWrapper.ps1: builds the artifact and asserts it parses, elevates before it extracts, and locks the extraction directory.
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What
Fixes a local privilege-escalation path in the standalone build (the shipped single-file artifact).
The wrapper extracted its base64 payload to a per-user
%TEMP%\Winnow_Run_<guid>and ran the extractedWinnow.ps1as the unelevated user;Ensure-Adminthen self-elevated via-Verb RunAs. So the elevated run dot-sourced its ~100 scripts from a directory the standard user still controls. A local user (or malware running as them) could overwrite one of those files between extraction and execution and have it run with the elevated process's rights.Same bug class as the watchdog ACL fix (#47): a privileged process trusting a location a non-admin can write.
Change
RunAs(passing args through with the existing Win32-safe quoting) and exit with the child's code.SetAccessRuleProtection($true,$false), inheritance off), so the user cannot write to it even though it lives under their%TEMP%.No UX change: today's flow already produces a UAC prompt and an elevated window (Winnow self-elevates); this just moves elevation ahead of extraction.
The modular path (running
Winnow.ps1from a source checkout) is unchanged and still elevates from wherever the tree lives; that path is for people running from source who control their own environment. Noted in the ledger.Validation
Tests\Invoke-StaticValidation.ps1 -RequirePSScriptAnalyzerclean (121 files).Tests/Unit/Test-StandaloneWrapper.ps1(Pester 5.7.1): 5/5 pass. Builds the real artifact and asserts it parses, elevates before it extracts (guard index precedesExpand-Archive), locks the extraction dir (SYSTEM + Administrators SIDs,SetAccessRuleProtection), and uses a full guid.Tests/Unit/Test-UpdateWatchdog.ps1: 16/16 pass (no regression).Not run here: the interactive RunAs elevation itself (needs a UAC prompt). New CI step added.