Reject unsafe Windows update cache segments

2026-07-12 22:37:51 -04:00
parent c0b9e17214
commit b076a84dc7
2 changed files with 12 additions and 0 deletions
@@ -276,10 +276,19 @@ function Normalize-PathForCompare($Path) {
    )
 }

+function Assert-NoRelativePathSegments($Path) {
+    foreach ($segment in ($Path -split '[\\/]')) {
+        if ($segment -eq "." -or $segment -eq "..") {
+            throw "refusing unsafe update cache path: $Path"
+        }
+    }
+}
+
 function Assert-SafeUpdateCache($Path) {
    if (-not $Path) {
        throw "refusing unsafe update cache path: $Path"
    }
+    Assert-NoRelativePathSegments $Path
    $full = Normalize-PathForCompare $Path
    $root = Normalize-PathForCompare ([System.IO.Path]::GetPathRoot($full))
    $homePath = Normalize-PathForCompare $HOME