Bug 1626184 (CVE-2018-13259)

Summary:	CVE-2018-13259 zsh: Improper handling of shebang line longer than 64
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dmaphy, james.antill, j, kdudka, svashisht
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	zsh 5.6	Doc Type:	If docs needed, set a value
Doc Text:	It was discovered that zsh does not properly validate the shebang of input files and it truncates it to the first 64 bytes. A local attacker may use this flaw to make zsh execute a different binary than what is expected, named with a substring of the shebang one.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-08-06 19:19:43 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:	1626185, 1626186, 1628990
Bug Blocks:	1626188

Description Pedro Sampaio 2018-09-06 17:23:22 UTC

An issue was discovered in zsh before 5.6. Shebang lines exceeding 64 characters were truncated, potentially leading to an execve call to a program name that is a substring of the intended one.

Upstream patch:

https://sourceforge.net/p/zsh/code/ci/1c4c7b6a4d17294df028322b70c53803a402233d

References:

https://www.zsh.org/mla/zsh-announce/136

Comment 1 Pedro Sampaio 2018-09-06 17:24:57 UTC

Created zsh tracking bugs for this issue:

Affects: fedora-all [bug 1626185]

Comment 3 Riccardo Schirone 2018-09-14 09:00:57 UTC

External References:

http://www.zsh.org/mla/zsh-announce/136

Comment 7 Riccardo Schirone 2018-09-14 15:18:38 UTC

Statement:

This issue did not affect the versions of zsh as shipped with Red Hat Enterprise Linux 5 as scripts were directly handled by the kernel and not special-handled by zsh itself.

Comment 8 errata-xmlrpc 2019-08-06 12:02:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:2017 https://access.redhat.com/errata/RHSA-2019:2017

Comment 9 Product Security DevOps Team 2019-08-06 19:19:43 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2018-13259