Use After Free Affecting bison package, versions *


Severity

Recommended
low

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.09% (40th percentile)

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  • Snyk IDSNYK-UBUNTU2004-BISON-609742
  • published25 Aug 2020
  • disclosed25 Aug 2020

Introduced: 25 Aug 2020

CVE-2020-24240  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for Ubuntu:20.04 bison.

NVD Description

Note: Versions mentioned in the description apply only to the upstream bison package and not the bison package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

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 Scores

version 3.1