An excessively large PDF page size (found in fuzz testing, unlikely in normal PDF files) can result in a divide-by-zero in Xpdf's text extraction code.
This is related to CVE-2022-30524, but the problem here is caused by a very large page size, rather than by a very large character coordinate.
An integer overflow was addressed with improved input validation. This issue is fixed in Security Update 2021-005 Catalina, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, watchOS 7.6.2. Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
There is an invalid memory access in the function GfxIndexedColorSpace::mapColorToBase() located in GfxState.cc in Xpdf 4.0.0, as used in pdfalto 0.2. It can be triggered by (for example) 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.