バージョン25.07.0より前のPopplerには、pdfseparateユーティリティのPDFDoc処理ロジックに脆弱性が存在します。自己参照または相互参照を行うように細工された「/Annots」ディクショナリは、「PDFDoc::markAnnotations --> PDFDoc::markPageObjects --> PDFDoc::markObject --> PDFDoc::markDictionary」において無限再帰を引き起こします。これは、ループ検出が辞書ポインタのアドレスを使用しており、そのアドレスがfetch()のたびに異なるためです。リモートの攻撃者は、悪意のあるPDFを処理させることで、サービス拒否（アプリケーションのハングまたはクラッシュ）を引き起こす可能性があります。
ここでは、悪意のあるPDF（poppler-pdfseparate-poc）を作成します。「/Annots」が自己参照または相互参照するディクショナリに解決されるため、PopplerのmarkAnnotations --> markPageObjects --> markObject --> markDictionary再帰はループを検出できず、コールスタックを消費し尽くします（無限再帰）。悪用にはPDFを開くか処理するだけで十分です（例：pdfseparate経由）。
再現手順は以下のとおりです：```bash afl_env(base) user@ubuntu:~/zgd/AFLProject/pdf_parsers/poppler-25.04.0/build/utils$ ./pdfseparate ./../../../../pdf_fuzz/p oppler-master/pdfseparate/analyze_crashes/only_custom/all_crashes/poppler-pdfseparate-poc /dev/null Segmentation fault (core dumped)
afl_env(base) user@ubuntu:/zgd/AFLProject/pdf_parsers/poppler-25.04.0/build/utils$ gdb ./pdfseparate core.2332378
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For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from ./pdfseparate... [New LWP 2332378] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". --Type for more, q to quit, c to continue without paging-- Core was generated by `./pdfseparate ./../../../../pdf_fuzz/poppler-master/pdfseparate/analyze_crashes'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007a27410a3dee in _int_malloc (av=av@entry=0x7a274121ac80 <main_arena>, bytes=bytes@entry=40) at ./malloc/malloc.c:3903 3903 ./malloc/malloc.c: No such file or directory. (gdb) bt #0 0x00007a27410a3dee in _int_malloc (av=av@entry=0x7a274121ac80 <main_arena>, bytes=bytes@entry=40) at ./malloc/malloc.c:3903 #1 0x00007a27410a5262 in __GI___libc_malloc (bytes=40) at ./malloc/malloc.c:3321 #2 0x00007a27414ae98c in operator new(unsigned long) () from /lib/x86_64-linux-gnu/libstdc++.so.6 #3 0x00007a274192a080 in __gnu_cxx::new_allocator<std::_Rb_tree_node >::allocate (this=0x5c29c1b2a498, __n=1) at /usr/include/c++/11/ext/new_allocator.h:127 #4 0x00007a2741929c8f in std::allocator<std::_Rb_tree_node >::allocate (__n=1, this=0x5c29c1b2a498) at /usr/include/c++/11/bits/allocator.h:185 #5 std::allocator_traits<std::allocator<std::_Rb_tree_node > >::allocate (__a=..., __n=1) at /usr/include/c++/11/bits/alloc_traits.h:464 #6 0x00007a274192974f in std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::_M_get_node (this=0x5c29c1b2a498) at /usr/include/c++/11/bits/stl_tree.h:561 #7 0x00007a2741973466 in std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::_M_create_node<int const&> (this=0x5c29c1b2a498) at /usr/include/c++/11/bits/stl_tree.h:611 #8 0x00007a2741970c97 in std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::_Alloc_node::operator()<int const&> (this=0x7ffeba55f200, __arg=@0x7ffeba55f2a0: 4) at /usr/include/c++/11/bits/stl_tree.h:529 #9 0x00007a274196ba22 in std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::M_insert<int const&, std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::_Alloc_node> ( this=0x5c29c1b2a498, __x=0x0, __p=0x5c29c1b2a4a0, __v=@0x7ffeba55f2a0: 4, __node_gen=...) at /usr/include/c++/11/bits/stl_tree.h:1784 #10 0x00007a2741963f5e in std::_Rb_tree<int, int, std::_Identity, std::less, std::allocator >::_M_insert_unique<int const&> (this=0x5c29c1b2a498, __v=@0x7ffeba55f2a0: 4) at /usr/include/c++/11/bits/stl_tree.h:2129 #11 0x00007a274195c4f6 in std::set<int, std::less, std::allocator >::insert (this=0x5c29c1b2a498, --Type for more, q to quit, c to continue without paging-- __x=@0x7ffeba55f2a0: 4) at /usr/include/c++/11/bits/stl_set.h:512 #12 0x00007a2741957c6d in RefRecursionChecker::insert (this=0x5c29c1b2a498, ref=...) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/Object.h:133 #13 0x00007a2741b0e09c in XRef::fetch (this=0x5c29c1b2a370, num=4, gen=0, recursion=0, endPos=0x0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/XRef.cc:1202 #14 0x00007a2741b0dfb4 in XRef::fetch (this=0x5c29c1b2a370, ref=..., recursion=0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/XRef.cc:1190 #15 0x00007a2741a94e1d in Object::fetch (this=0x5c29c208a1c0, xref=0x5c29c1b2a370, recursion=0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/Object.cc:110 #16 0x00007a27419785d3 in Array::get (this=0x5c29c208a160, i=0, recursion=0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/Array.cc:92 #17 0x00007a2741ab0514 in PDFDoc::markAnnotations (this=0x5c29c1b2a0a0, annotsObj=0x7ffeba55f6b0, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldPageNum=3, newPageNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1856 #18 0x00007a2741aaf6b3 in PDFDoc::markDictionary (this=0x5c29c1b2a0a0, dict=0x5c29c208a100, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1716 #19 0x00007a2741aaf8d8 in PDFDoc::markObject (this=0x5c29c1b2a0a0, obj=0x7ffeba55f800, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1744 #20 0x00007a2741ab03af in PDFDoc::markPageObjects (this=0x5c29c1b2a0a0, pageDict=0x5c29c208a0a0, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1840 --Type for more, q to quit, c to continue without paging-- #21 0x00007a2741ab0827 in PDFDoc::markAnnotations (this=0x5c29c1b2a0a0, annotsObj=0x7ffeba55f9a0, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldPageNum=3, newPageNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1889 #22 0x00007a2741aaf6b3 in PDFDoc::markDictionary (this=0x5c29c1b2a0a0, dict=0x5c29c2089f10, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1716 #23 0x00007a2741aaf8d8 in PDFDoc::markObject (this=0x5c29c1b2a0a0, obj=0x7ffeba55faf0, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1744 #24 0x00007a2741ab03af in PDFDoc::markPageObjects (this=0x5c29c1b2a0a0, pageDict=0x5c29c2089eb0, xRef=0x5c29c1b2b080, countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0) at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1840
