Bug 1515713 (CVE-2017-16544)

Summary:	CVE-2017-16544 busybox: Insufficient sanitization of filenames when autocompleting
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	admiller, athmanem, dkholia, dvlasenk, mpoole
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	It was found that the tab auto-completion feature of BusyBox did not sanitize filenames, leading to execution of arbitrary escape sequences in the terminal emulator. Exploitation of this flaw by an attacker could potentially result in code execution, arbitrary file writes, or other attacks under highly specific circumstances dependent on the usage of a vulnerable terminal emulator by the user.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-12-26 10:27:15 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:	1515259
Bug Blocks:	1515717

Description Andrej Nemec 2017-11-21 09:26:35 UTC

In the add_match function in libbb/lineedit.c in BusyBox through 1.27.2, the tab autocomplete feature of the shell, used to get a list of filenames in a directory, does not sanitize filenames and results in executing any escape sequence in the terminal. This could potentially result in code execution, arbitrary file writes, or other attacks when combined with the usage of vulnerable / buggy terminal emulators.

Upstream patch:

https://git.busybox.net/busybox/commit/?id=c3797d40a1c57352192c6106cc0f435e7d9c11e8

External References:

https://www.twistlock.com/2017/11/20/cve-2017-16544-busybox-autocompletion-vulnerability/

Comment 1 Andrej Nemec 2017-11-21 09:27:25 UTC

Created busybox tracking bugs for this issue:

Affects: fedora-all [bug 1515259]