Multiple integer overflows in the Render extension in the X server 1.4 in X.Org X11R7.3 allow context-dependent attackers to execute arbitrary code via a (1) SProcRenderCreateLinearGradient, (2) SProcRenderCreateRadialGradient, or (3) SProcRenderCreateConicalGradient request with an invalid field specifying the number of bytes to swap in the request data, which triggers heap memory corruption.
Weaknesses in this category are related to improper calculation or conversion of numbers.