Home / exploits ImageMagick BMP Coder Out-Of-Bounds Write Vulnerability
Posted on 30 November -0001
<HTML><HEAD><TITLE>ImageMagick BMP Coder Out-Of-Bounds Write Vulnerability</TITLE><META http-equiv="Content-Type" content="text/html; charset=utf-8"></HEAD><BODY>Hi. This is PwChen of Tencent's Xuanwu Lab & RayZhong of Tencent's Keen Lab. During our research, we found an Out-Of-Bounds write vulnerability in ImageMagick's BMP coders. When ImageMagick is converting other format to BMP format, it will pass image's height and width parameter into 'BMP coder'. There is an arithmetic overflow vulnerability when the BMP coder is calculating the image size by multiplying the height and width. This can directly cause an Out-Of-Bounds Write. The ImageMagick team has fixed the vulnerability we reported. Attached is a proof of concept. python -c 'print "P3x0a14096x201048576x0a255x00"' > PoC.ppm convert PoC.ppm crash.bmp Upstream fix: https://github.com/ImageMagick/ImageMagick/commit/e7094d16cd8aee6bb48cf1d369f617f7edf89993 https://github.com/ImageMagick/ImageMagick/commit/4cc6ec8a4197d4c008577127736bf7985d632323 Debian Bug report: https://bugs.debian.org/834504 Regards, Peiwen Chen Tencent's Xuanwu Lab </BODY></HTML>
