Created attachment 1299843 [details] Triggered by "./sassc POC4" Description of problem: There is a stack-overflow in the sassc of libsass library. This vulnerability was triggered in function Parser::advanceToNextToken() at line /libsass/src/parser.cpp:66. Version-Release number of selected component (if applicable): <= latest version How reproducible: ./sassc $POC Steps to Reproduce: The debugging information is as follows: $ ./sassc POC4 Segmentation fault ASAN debugging information: $ ./sassc POC4 ASAN:SIGSEGV ================================================================= ==102693==ERROR: AddressSanitizer: stack-overflow on address 0x7fff6af5ac08 (pc 0x0000004a6f1d bp 0x7fff6af5b470 sp 0x7fff6af5ac10 T0) #0 0x4a6f1c (/home/icy/secreal/sassc-asan/install/bin/sassc+0x4a6f1c) #1 0x7f45522d527d (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x46027d) #2 0x7f455229ec19 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x429c19) #3 0x7f45522d3cdc (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x45ecdc) #4 0x7f45522ce835 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x459835) #5 0x7f45522e393a (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x46e93a) #6 0x7f45522e1a81 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x46ca81) #7 0x7f45522d9611 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x464611) #8 0x7f45522d7e68 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x462e68) #9 0x7f45522d628c (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x46128c) #10 0x7f45522d529c (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x46029c) .... #251 0x7f45522d7e68 (/home/icy/secreal/libsass-asan/install/lib/libsass.so.1+0x462e68) ==102693==ABORTING GDB debugging information: (gdb) set args POC4 (gdb) b parser.cpp:66 (gdb) r The program being debugged has been started already. ... Breakpoint 1, Sass::Parser::advanceToNextToken (this=0x7fffffffd930) at parser.cpp:66 66 pstate.offset.line = 0; (gdb) c 3025 Continuing. Breakpoint 1, Sass::Parser::advanceToNextToken (this=0x7fffffffd930) at parser.cpp:66 66 pstate.offset.line = 0; (gdb) n r Program received signal SIGSEGV, Segmentation fault. 0x00000000004a6f1d in __asan_memset () (gdb) i b Num Type Disp Enb Address What 1 breakpoint keep y <MULTIPLE> breakpoint already hit 3206 times 1.1 y 0x00007ffff76c389a in Sass::Parser::advanceToNextToken() at parser.cpp:66 1.2 y 0x00007ffff770d81f in Sass::Parser::parse_media_queries() at parser.cpp:66 1.3 y 0x00007ffff77215d7 in Sass::Parser::parse_complex_selector(bool) at parser.cpp:66 1.4 y 0x00007ffff7748276 in Sass::Parser::parse_disjunction() at parser.cpp:66 1.5 y 0x00007ffff7749266 in Sass::Parser::parse_conjunction() at parser.cpp:66 1.6 y 0x00007ffff774ae42 in Sass::Parser::parse_relation() at parser.cpp:66 1.7 y 0x00007ffff774c5ea in Sass::Parser::parse_expression() at parser.cpp:66 1.8 y 0x00007ffff7754a57 in Sass::Parser::parse_operators() at parser.cpp:66 1.9 y 0x00007ffff777c695 in Sass::Parser::parse_media_query() at parser.cpp:66 (gdb) bt #0 0x00000000004a6f1d in __asan_memset () #1 0x00007ffff774827e in Sass::Parser::advanceToNextToken (this=0x7fffffffd930) at parser.cpp:66 #2 Sass::Parser::parse_disjunction (this=<optimized out>) at parser.cpp:1216 #3 0x00007ffff7711c1a in Sass::Parser::parse_space_list (this=0x7fffffffd930) at parser.cpp:1192 #4 0x00007ffff7746cdd in Sass::Parser::parse_comma_list (this=<optimized out>, delayed=false) at parser.cpp:1162 #5 0x00007ffff7741836 in Sass::Parser::parse_list (this=0x7fffffffd930, delayed=false) at parser.cpp:1147 #6 Sass::Parser::parse_map (this=<optimized out>) at parser.cpp:1058 #7 0x00007ffff775693b in Sass::Parser::parse_factor (this=0x7fffffffd930) at parser.cpp:1389 #8 0x00007ffff7754a82 in Sass::Parser::parse_operators (this=<optimized out>) at parser.cpp:1356 #9 0x00007ffff774c612 in Sass::Parser::parse_expression (this=<optimized out>) at parser.cpp:1316 #10 0x00007ffff774ae69 in Sass::Parser::parse_relation (this=<optimized out>) at parser.cpp:1262 #11 0x00007ffff774928d in Sass::Parser::parse_conjunction (this=<optimized out>) at parser.cpp:1240 #12 0x00007ffff774829d in Sass::Parser::parse_disjunction (this=<optimized out>) at parser.cpp:1219 #13 0x00007ffff7711c1a in Sass::Parser::parse_space_list (this=0x7fffffffd930) at parser.cpp:1192 #14 0x00007ffff7746cdd in Sass::Parser::parse_comma_list (this=<optimized out>, delayed=false) at parser.cpp:1162 ... This vulnerability was triggered in function Parser::advanceToNextToken() at line /libsass/src/parser.cpp:66: 61 void Parser::advanceToNextToken() { 62 lex < css_comments >(false); 63 // advance to position 64 pstate += pstate.offset; 65 pstate.offset.column = 0; 66 pstate.offset.line = 0; 67 } Actual results: crash Expected results: crash Additional info: Credits: This vulnerability is detected by team OWL337, with our custom fuzzer collAFL. Please contact ganshuitao and chaoz.cn if you need more info about the team, the tool or the vulnerability.
Reported upstream as https://github.com/sass/libsass/issues/2447
This bug appears to have been reported against 'rawhide' during the Fedora 27 development cycle. Changing version to '27'.
*** Bug 1482332 has been marked as a duplicate of this bug. ***
This message is a reminder that Fedora 27 is nearing its end of life. On 2018-Nov-30 Fedora will stop maintaining and issuing updates for Fedora 27. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '27'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 27 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
It appears this bug was missed in the EOL closure for F27 on 2018-11-30. If this bug still exists on supported versions, please reopen and update the version. If you cannot update the version, please needinfo the assignee.