Bug 1468427 (CVE-2017-1000082)

Summary:	CVE-2017-1000082 systemd: fails to parse usernames that start with digits
Product:	[Other] Security Response	Reporter:	Doran Moppert <dmoppert>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	johannbg, lnykryn, msekleta, muadda, ssahani, s, systemd-maint-list, systemd-maint, zbyszek
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-07-07 04:53:26 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:	1468430
Bug Blocks:	1467225

Description Doran Moppert 2017-07-07 04:30:28 UTC

Systemd version 323 rejects usernames starting with a digit (eg "0day"),
running the service with root privileges even though a corresponding user
exists.

Upstream bug:

https://github.com/systemd/systemd/issues/6237

oss-sec discussion:

http://www.openwall.com/lists/oss-security/2017/07/02/1

Comment 1 Doran Moppert 2017-07-07 04:40:47 UTC

This issue seems to have been introduced since systemd-229.  Neither EL7 nor Fedora 24 is affected - not sure about 231/233.

For an attacker to exploit this they would need to influence the creation of a user and associated unit file on the system.

Comment 2 Doran Moppert 2017-07-07 04:52:25 UTC

Created systemd tracking bugs for this issue:

Affects: fedora-all [bug 1468430]

Comment 3 Doran Moppert 2017-07-10 06:45:23 UTC

Statement:

For more information on the impact of numeric usernames in Red Hat Enterprise Linux, please see https://access.redhat.com/solutions/3103631