cve/2020/CVE-2020-24240.md

CVE-2020-24240

Description

GNU Bison before 3.7.1 has a use-after-free in _obstack_free in lib/obstack.c (called from gram_lex) when a '\0' byte is encountered. NOTE: there is a risk only if Bison is used with untrusted input, and the observed bug happens to cause unsafe behavior with a specific compiler/architecture. The bug report was intended to show that a crash may occur in Bison itself, not that a crash may occur in code that is generated by Bison.

POC

Reference

• https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html
• https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html

Github

No PoCs found on GitHub currently.