There is an invalid memory access vulnerability in the function TextPage::findGaps() located at TextOutputDev.c in Xpdf 4.01, which can (for example) be triggered by sending a crafted pdf file to the pdftops binary. It allows an attacker to cause Denial of Service (Segmentation fault) or possibly have unspecified other impact.
CWE-125 - Out-of-Bounds Read
Out-of-bounds read is a vulnerability that allows access to memory beyond the authorized accessible location. Such a vulnerability compromises the confidentiality of the trusted environment in the application and enables an attacker to launch further attacks by leveraging the exposed information.