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.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2020-24240)

Note that Nessus relies on the presence of the package as reported by the vendor.

According to the versions of the bison packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - 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. (CVE-2020-24240)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
255411	Linux Distros Unpatched Vulnerability : CVE-2020-24240	Nessus	Misc.	medium
166844	EulerOS 2.0 SP10 : bison (EulerOS-SA-2022-2674)	Nessus	Huawei Local Security Checks	medium
166837	EulerOS 2.0 SP10 : bison (EulerOS-SA-2022-2642)	Nessus	Huawei Local Security Checks	medium

Detections

Analytics

CVE-2020-24240

medium

Tenable Plugins

medium

medium

medium