Catalyzes the hydrolysis of complex carboxylic polyesters found in the cell wall of plants (PubMed:17704215). Degrades cutin, a macromolecule that forms the structure of the plant cuticle (PubMed:17704215). Required for efficient penetration of the host plant cuticle by the appressorium during the initial stage of fungal infection (PubMed:17704215). cutin + H2O = cutin monomers. Induced during infection; levels are increased during germ tube and appressorium differentiation, and during penetration. The 2 disulfide bonds play a critical role in holding the catalytic residues in juxta-position; reduction of the disulfide bridges results in the complete inactivation of the enzyme. Decreases secreted carboxylic ester hydrolase activity during growth on cutin carbon source (PubMed:17704215). Decreases conidiation and results in abnormal germling morphology (PubMed:17704215). Impairs penetration of the host epidermis and decreases virulence in rice and wheat (PubMed:17704215). Belongs to the cutinase family.