CVE-2020-24240

EUVD-2020-16975
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 60%
Affected Products (NVD)
VendorProductVersion
gnubison
3.7
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
bison
bookworm
2:3.8.2+dfsg-1
fixed
bullseye
2:3.7.5+dfsg-1
fixed
buster
not-affected
sid
2:3.8.2+dfsg-1
fixed
stretch
not-affected
trixie
2:3.8.2+dfsg-1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
bison
bionic
needed
focal
needed
groovy
ignored
hirsute
ignored
impish
ignored
jammy
needed
kinetic
ignored
lunar
not-affected
mantic
not-affected
noble
not-affected
trusty
dne
xenial
needed
Common Weakness Enumeration
References
https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68d
https://github.com/akimd/bison/compare/v3.7...v3.7.1
https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html
https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68d
https://github.com/akimd/bison/compare/v3.7...v3.7.1
https://lists.gnu.org/r/bug-bison/2020-07/msg00051.html