Race condition in gdImageStringFTEx (gdft_draw_bitmap) in gdft.c in the GD Graphics Library (libgd) before 2.0.35 allows user-assisted remote attackers to cause a denial of service (crash) via unspecified vectors, possibly involving truetype font (TTF) support.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.