Badosa claimed the biggest win of her career so far in the quarter-finals when she knocked out Australia's world No.1 Barty.
But the 23-year-old, twice beaten in the semis at WTA 250-level events in the past year, came up short against No.15 seed Kudermetova.
The Russian was clinical, taking four of her six break-point opportunities in a straightforward 6-3 6-3 success.
Kudermetova had previously knocked out Sloane Stephens but will now be favourite against Danka Kovinic.
The underdog's straight-sets defeat of Ons Jabeur in the last four should ensure there is no complacency from Kudermetova.
In Bogota, 19-year-old wildcard Maria Camila Osorio Serrano will play for the title after swatting aside qualifier Harmony Tan 6-1 6-2.
The former top-ranked junior will have to negotiate No.5 seed Tamara Zidansek, however, after she defeated Viktoriya Tomova 6-3 7-5.
