Bug 1549862 (CVE-2017-18205)

Summary:	CVE-2017-18205 zsh: NULL dereference in cd in sh compatibility mode under given circumstances
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dmaphy, james.antill, j, kdudka, svashisht
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	zsh 5.4	Doc Type:	If docs needed, set a value
Doc Text:	A NULL pointer dereference flaw was found in the code responsible for the cd builtin command of the zsh package. An attacker could use this flaw to cause a denial of service by crashing the user shell.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-11-30 00:30:00 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1570881, 1570882
Bug Blocks:	1549839

Description Laura Pardo 2018-02-27 22:36:40 UTC

A flaw was found in zsh prior 5.3.1. There is a vulnerability when in sh compatibility mode if HOME was not set
and cd was used with no argument.


References:
https://sourceforge.net/p/zsh/code/ci/eb783754bdb74377f3cea4ceca9c23a02ea1bf58

Comment 1 Kamil Dudka 2018-03-06 14:08:24 UTC

(In reply to Laura Pardo from comment #0)
> A flaw was found in zsh prior 5.3.1.

The commit you refer to landed (217 commits) _after_ the 5.3.1 release.

Comment 2 Kamil Dudka 2018-03-06 15:47:00 UTC

fixed in zsh-5.3.1-7.fc26

Comment 5 errata-xmlrpc 2018-10-30 07:30:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:3073 https://access.redhat.com/errata/RHSA-2018:3073