In LibTIFF 4.0.8, there is a denial of service vulnerability in the TIFFOpen function. A crafted input will lead to a denial of service attack. During the TIFFOpen process, td_imagelength is not checked. The value of td_imagelength can be directly controlled by an input file. In the ChopUpSingleUncompressedStrip function, the _TIFFCheckMalloc function is called based on td_imagelength. If we set the value of td_imagelength close to the amount of system memory, it will hang the system or trigger the OOM killer. (CVE-2017-11613) In LibTIFF 4.0.9, there is an uncontrolled resource consumption in the TIFFSetDirectory function of tif_dir.c. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted tif file. This occurs because the declared number of directory entries is not validated against the actual number of directory entries. (CVE-2018-5784)