{"id":"DEBIAN-CVE-2020-24240","details":"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.","modified":"2026-09-01T16:04:59.238135993Z","published":"2020-08-25T14:15:16.543Z","upstream":["CVE-2020-24240"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2020-24240"}],"affected":[{"package":{"name":"bison","ecosystem":"Debian:12","purl":"pkg:deb/debian/bison?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.7.2+dfsg-1"}]}],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-24240.json"}},{"package":{"name":"bison","ecosystem":"Debian:13","purl":"pkg:deb/debian/bison?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.7.2+dfsg-1"}]}],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-24240.json"}},{"package":{"name":"bison","ecosystem":"Debian:14","purl":"pkg:deb/debian/bison?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.7.2+dfsg-1"}]}],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-24240.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}