xpdf 4.04 allocates excessive memory when presented with crafted input. This can be triggered by (for example) sending a crafted PDF document to the pdftoppm binary. It is most easily reproduced with the DCMAKE_CXX_COMPILER=afl-clang-fast++ option.
There is an invalid memory access in the TextLine class in TextOutputDev.cc in Xpdf 4.0.4 because the text extractor mishandles characters at large y coordinates. It can be triggered by (for example) sending a crafted pdf file to the pdftotext binary, which allows a remote attacker to cause a Denial of Service (Segmentation fault) or possibly have unspecified other impact.
xpdf 4.03 has heap buffer overflow in the function readXRefTable located in XRef.cc. An attacker can exploit this bug to cause a Denial of Service (Segmentation fault) or other unspecified effects by sending a crafted PDF file to the pdftoppm binary.
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.
Xpdf 4.02 allows stack consumption because of an incorrect subroutine reference in a Type 1C font charstring, related to the FoFiType1C::getOp() function.
In Xpdf 4.02, SplashOutputDev::endType3Char(GfxState *state) SplashOutputDev.cc:3079 is trying to use the freed `t3GlyphStack->cache`, which causes an `heap-use-after-free` problem. The codes of a previous fix for nested Type 3 characters wasn't correctly handling the case where a Type 3 char referred to another char in the same Type 3 font.
There is an invalid memory access in the function TextString::~TextString() located in Catalog.cc in Xpdf 4.0.2. It can be triggered by (for example) sending a crafted pdf file to the pdftohtml binary, which allows a remote attacker to cause a Denial of Service (Segmentation fault) or possibly have unspecified other impact.
There is an invalid memory access in the function fprintf located in Error.cc in Xpdf 4.0.2. It can be triggered by sending a crafted PDF file to the pdftohtml binary, which allows a remote attacker to cause a Denial of Service (Segmentation fault) or possibly have unspecified other impact.