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Vulnerability · Published Aug 25, 2020 · Assigned by mitre

CVE-2020-24240

Medium 5.5

In plain English

A medium-severity security flaw in the bison package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 70% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)1.3%top 29.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20bison3.7.2-r0ALPINE-CVE-2020-24240
Alpine:v3.21bison3.7.2-r0ALPINE-CVE-2020-24240
Alpine:v3.22bison3.7.2-r0ALPINE-CVE-2020-24240
Alpine:v3.23bison3.7.2-r0ALPINE-CVE-2020-24240
Alpine:v3.24bison3.7.2-r0ALPINE-CVE-2020-24240
Debian:12bison2:3.7.2+dfsg-1DEBIAN-CVE-2020-24240
Debian:13bison2:3.7.2+dfsg-1DEBIAN-CVE-2020-24240
Debian:14bison2:3.7.2+dfsg-1DEBIAN-CVE-2020-24240

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References