CVE-2020-24240
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.
Does this matter?
Lower severity and a low EPSS score (1.26%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- EPSS
- 1.26% probability · 68th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- gnu/bison
- Source
- cve@mitre.org
References
- https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68dPatch, Third Party Advisory
- https://github.com/akimd/bison/compare/v3.7...v3.7.1Third Party Advisory
- https://lists.gnu.org/r/bug-bison/2020-07/msg00051.htmlMailing List, Vendor Advisory
- https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68dPatch, Third Party Advisory
- https://github.com/akimd/bison/compare/v3.7...v3.7.1Third Party Advisory
- https://lists.gnu.org/r/bug-bison/2020-07/msg00051.htmlMailing List, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.