CVE-2019-14868

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-04-02 · updated 2026-06-17
Weakness: CWE-77

Description

In ksh version 20120801, a flaw was found in the way it 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.

Affected products

macOS: before 10.15.5 — fixed in 10.15.5
Debian Linux: 9.0
Ksh Project Ksh: 20120801

How to fix

Upgrade to a fixed version: macOS 10.15.5. Check the vendor advisory for mitigations.

References

http://seclists.org/fulldisclosure/2020/May/53
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14868
https://github.com/att/ast/commit/c7de8b641266bac7c77942239ac659edfee9ecd2
https://lists.debian.org/debian-lts-announce/2020/07/msg00015.html
https://support.apple.com/kb/HT211170
http://seclists.org/fulldisclosure/2020/May/53
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14868
https://github.com/att/ast/commit/c7de8b641266bac7c77942239ac659edfee9ecd2
https://lists.debian.org/debian-lts-announce/2020/07/msg00015.html
https://support.apple.com/kb/HT211170

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