FreeBSD : ksh93 -- certain environment variables interpreted as arithmetic expressions on startup, leading to code injection (8b20d716-49df-11ea-9f7b-206a8a720317)

high Nessus Plugin ID 133588


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The remote FreeBSD host is missing one or more security-related updates.


Upstream ksh93 maintainer Siteshwar Vashisht reports :

A flaw was found in the way ksh evaluates certain environment variables. An attacker could use this flaw to override or bypass environment restrictions to execute shell commands. Services and applications that allow remote unauthenticated attackers to provide one of those environment variables could allow them to exploit this issue remotely.


Update the affected packages.

See Also

Plugin Details

Severity: High

ID: 133588

File Name: freebsd_pkg_8b20d71649df11ea9f7b206a8a720317.nasl

Version: 1.2

Type: local

Published: 2/10/2020

Updated: 2/24/2020

Dependencies: ssh_get_info.nasl

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:ksh93, p-cpe:/a:freebsd:freebsd:ksh93-devel, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Patch Publication Date: 2/7/2020

Vulnerability Publication Date: 10/1/2019