CVEvulnerability
CVE-2020-24240
5.5 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2020-08-25
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- CVSS 2.0 ([email protected])
- 7.1 HIGH — AV:N/AC:M/Au:N/C:N/I:N/A:C
- Weaknesses
- CWE-416
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.
Affected configurations
• gnu bison 3.7
Related
Weakness · CWE (1)
- CWE-416 Use After Free weakness
References
- https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68d Patch, Third Party Advisory
- https://github.com/akimd/bison/compare/v3.7...v3.7.1 Third Party Advisory
- https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html Mailing List, Vendor Advisory
- https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68d Patch, Third Party Advisory
- https://github.com/akimd/bison/compare/v3.7...v3.7.1 Third Party Advisory
- https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html Mailing List, Vendor Advisory