system
Describe <CVE-2017-7890>.
user
What is <CVE-2017-7890>?
assistant
The GIF decoding function gdImageCreateFromGifCtx in gd_gif_in.c in the GD Graphics Library (aka libgd), as used in PHP before 5.6.31 and 7.x before 7.1.7, does not zero colorMap arrays before use. A specially crafted GIF image could use the uninitialized tables to read ~700 bytes from the top of the stack, potentially disclosing sensitive information..