case 4690 - AdminConnectionString: swap only the database via NpgsqlConnectionStringBuilder

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

devdocs/modernization/NET10-PORT.md

@@ -113,7 +113,7 @@ Sockeye included its equivalents in the port branch. John decides per item wheth
 in this branch or a follow-up release. UPDATE: John has decided these all go in this branch and some more additional cases in the case database that are urgent, exact cases TBD.
 
 - [x] **Case 4676: data-list SQL injection — priority.** Confirmed: `DataListSqlFilterCriteriaBuilder` appended the raw filter value for Roles and for every numeric type (Enum, MemorySize, Decimal, Currency, InternalId, Integer). Text and tag values escape `'`; TimeSpan goes through `int.Parse`. Any authenticated user who can open a data list could reach this. **Sockeye's fix (`3427cd8`) is incomplete:** it checks only Decimal/Currency and Integer, and leaves InternalId, Enum, MemorySize and Roles open (still open in Sockeye 8.1.0). AyaNova's fix parses every numeric type as an invariant `decimal` (Decimal, Currency) or `long` (the rest), and Roles as a `long`, then appends the re-formatted number. An invalid value throws `ArgumentException`, which the API returns as an error before any SQL runs
-- [ ] **`DbUtil.AdminConnectionString`.** Confirmed: `DbUtil.cs:99` is `_dbConnectionString.Replace(_dbName, "postgres")`, used by the boot check (`:192`), create (`:286`) and drop/recreate (`:334`). Any customer whose role name, password or host contains the database name as text gets a mangled admin connection, and the boot check authenticates as the wrong user. Fix: `new NpgsqlConnectionStringBuilder(cs) { Database = "postgres" }.ConnectionString`
+- [x] **`DbUtil.AdminConnectionString`.** Fixed with the builder below (Sockeye 8.1.0 still has the `Replace`). Confirmed: `DbUtil.cs:99` is `_dbConnectionString.Replace(_dbName, "postgres")`, used by the boot check (`:192`), create (`:286`) and drop/recreate (`:334`). Any customer whose role name, password or host contains the database name as text gets a mangled admin connection, and the boot check authenticates as the wrong user. Fix: `new NpgsqlConnectionStringBuilder(cs) { Database = "postgres" }.ConnectionString`
 - [ ] **Backup `pg_dump` call.** Confirmed: `CoreJobBackup.cs:68` builds `postgresql://user:password@host:port/db` with the raw password, and `:94` adds `-Fc > file`; `RunProgram` runs it through `cmd.exe /C` (`RunProgram.cs:55`) or `/bin/sh -c` (`:82-89`). A password with spaces or `@ : / ? # %` breaks backups. Also, on Linux stderr is not redirected (`RunProgram.cs:86-92`), so a failed pg_dump returns empty output and is **reported as a successful backup** (`CoreJobBackup.cs:97`). Fix: password in `PGPASSWORD` in the process environment, connection parameters as separate arguments through `ProcessStartInfo.ArgumentList` (no shell), output with `-f`, stderr and exit code checked
 - [ ] **Drop-and-recreate database.** Confirmed: `DbUtil.cs:342-345` drops, then creates; triggered by `AYANOVA_PERMANENTLY_ERASE_DATABASE` (`Startup.cs:567-570`). Without `CREATEDB` it drops the database and then fails to create it. Test the permission before dropping, or change the order
 - [ ] **Report browser download location.** Confirmed: `new BrowserFetcher()` with the default path beside the app (`ReportBiz.cs:800`). Point it under the data directory in code. Beside the app it is read-only under a hardened systemd unit (`ProtectSystem=strict`), and a redeploy that replaces the app folder deletes it
@@ -187,3 +187,4 @@ Found during the port, out of scope. One line each.
 | 2026-10-22 | Survey of sections 1–3 against the code (read-only) | Findings recorded per item: n/a items ticked with reasons, evidence added, MiniProfiler found present |
 | 2026-10-22 | Integration baseline, `eb607d34` (unmodified, .NET 8.0.24, fresh test database) | 103 tests: 96 passed, 2 failed (the two known server bugs), 5 skipped |
 | 2026-10-22 | Case 4676 data-list SQL injection fix (.NET 8) | Integration suite same as baseline. API probe: valid Integer, Decimal and Roles filters return rows; `0 OR 1=1`, `0); select pg_sleep(3); --`, `1)=1 OR (1` and similar are rejected with `ArgumentException` before any SQL runs |
+| 2026-10-22 | `AdminConnectionString` via `NpgsqlConnectionStringBuilder` (.NET 8) | Boot database check passes; integration suite same as baseline. Old vs new on sample strings: old turned role `AyaNova` and password `AyaNova@1 x` into `postgres`, and host `ayanova.example.com` into `postgres.example.com`; new changes only `Database`. The section 4 role test still applies |

server/AyaNova/util/DbUtil.cs

@@ -96,7 +96,8 @@ namespace AyaNova.Util
         {
             get
             {
-                return _dbConnectionString.Replace(_dbName, "postgres");
+                //Swap only the database, a text replace also changed a user, password or host containing the database name
+                return new Npgsql.NpgsqlConnectionStringBuilder(_dbConnectionString) { Database = "postgres" }.ConnectionString;
             }
 
         }