CVE-2025-50420

أقرّ المطوّر (freedesktop، القائم على صيانة Poppler) بالمشكلة وأصلح الخلل. تم تطبيق الإصلاح في المستودع الرسمي الخاص به.

فيما يلي الرابط العام للتصحيح / الالتزام المقدّم من المطوّر:

https://gitlab.freedesktop.org/poppler/poppler/-/issues/1613<br>
https://gitlab.freedesktop.org/poppler/poppler/-/merge_requests/1849<br>
https://gitlab.freedesktop.org/poppler/poppler/-/commit/08d7894e4dd0e313c179e30f06ad8f546619b1b3

وهذا يؤكد أن الثغرة قد تم الاعتراف بها ومعالجتها.



توجد ثغرة في إصدارات Poppler قبل 25.07.0 في منطق معالجة PDFDoc بأداة pdfseparate: يتسبب قاموس «/Annots» المصمّم بعناية (يشير إلى نفسه أو إلى مراجع متبادلة) في تكرار لا نهائي داخل «PDFDoc::markAnnotations --> PDFDoc::markPageObjects --> PDFDoc::markObject --> PDFDoc::markDictionary»، لأن عنوان مؤشر القاموس المستخدم في اكتشاف الحلقات يتغير في كل مرة يتم فيها استدعاء fetch(). يمكن للمهاجم عن بُعد التسبب في رفض الخدمة (تعليق التطبيق أو تعطّله) من خلال معالجة ملف PDF خبيث.

هنا قمت بإنشاء ملف PDF خبيث (poppler-pdfseparate-poc)، حيث يتم تحليل «/Annots» إلى قاموس يشير إلى نفسه أو إلى مراجع متبادلة، مما يمنع اكتشاف الحلقة في التكرار markAnnotations --> markPageObjects --> markObject --> markDictionary في Poppler، وبالتالي استنفاد مكدس الاستدعاءات (تكرار لا نهائي). يكفي لاستغلال هذه الثغرة مجرد فتح ملف PDF أو معالجته (على سبيل المثال، باستخدام دالة pdfseparate).

خطوات إعادة الإنتاج كما يلي:```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 12.1-0ubuntu1~22.04.2) 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/>.
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    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
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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 <RET> 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<int> >::allocate (this=0x5c29c1b2a498, __n=1)
    at /usr/include/c++/11/ext/new_allocator.h:127
#4  0x00007a2741929c8f in std::allocator<std::_Rb_tree_node<int> >::allocate (__n=1, this=0x5c29c1b2a498)
    at /usr/include/c++/11/bits/allocator.h:185
#5  std::allocator_traits<std::allocator<std::_Rb_tree_node<int> > >::allocate (__a=..., __n=1)
    at /usr/include/c++/11/bits/alloc_traits.h:464
#6  0x00007a274192974f in std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::_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<int>, std::less<int>, std::allocator<int> >::_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<int>, std::less<int>, std::allocator<int> >::_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<int>, std::less<int>, std::allocator<int> >::_M_insert_<int const&, std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::_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<int>, std::less<int>, std::allocator<int> >::_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<int>, std::allocator<int> >::insert (this=0x5c29c1b2a498, 
--Type <RET> 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 <RET> 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
#25 0x00007a2741ab0827 in PDFDoc::markAnnotations (this=0x5c29c1b2a0a0, annotsObj=0x7ffeba55fc90, 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
#26 0x00007a2741aaf6b3 in PDFDoc::markDictionary (this=0x5c29c1b2a0a0, dict=0x5c29c2089d20, 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
#27 0x00007a2741aaf8d8 in PDFDoc::markObject (this=0x5c29c1b2a0a0, obj=0x7ffeba55fde0, 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
#28 0x00007a2741ab03af in PDFDoc::markPageObjects (this=0x5c29c1b2a0a0, pageDict=0x5c29c2089cc0, xRef=0x5c29c1b2b080, 
    countRef=0x5c29c1b2b240, numOffset=0, oldRefNum=3, newRefNum=259, alreadyMarkedDicts=0x5c29c1b2c9f0)
--Type <RET> for more, q to quit, c to continue without paging--
    at /home/user/zgd/AFLProject/pdf_parsers/poppler-25.04.0/poppler/PDFDoc.cc:1840
#29 0x00007a2741ab0827 in PDFDoc::markAnnotations (this=0x5c29c1b2a0a0, annotsObj=0x7ffeba55ff80, 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
#30 0x00007a2741aaf6b3 in PDFDoc::markDictionary (this=0x5c29c1b2a0a0, dict=0x5c29c2089b30, 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