Bug 1892436 (CVE-2020-15238)

Summary:	CVE-2020-15238 blueman: local privilege escalation in org.blueman.Mechanism D-Bus interface
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	fedora, nushio
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:	2020-10-28 20:21:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1892437
Bug Blocks:

Description Guilherme de Almeida Suckevicz 2020-10-28 18:52:28 UTC

Blueman is a GTK+ Bluetooth Manager. In Blueman before 2.1.4, the DhcpClient method of the D-Bus interface to blueman-mechanism is prone to an argument injection vulnerability. The impact highly depends on the system configuration. If Polkit-1 is disabled and for versions lower than 2.0.6, any local user can possibly exploit this. If Polkit-1 is enabled for version 2.0.6 and later, a possible attacker needs to be allowed to use the `org.blueman.dhcp.client` action. That is limited to users in the wheel group in the shipped rules file that do have the privileges anyway. On systems with ISC DHCP client (dhclient), attackers can pass arguments to `ip link` with the interface name that can e.g. be used to bring down an interface or add an arbitrary XDP/BPF program. On systems with dhcpcd and without ISC DHCP client, attackers can even run arbitrary scripts by passing `-c/path/to/script` as an interface name. Patches are included in 2.1.4 and master that change the DhcpClient D-Bus method(s) to accept BlueZ network object paths instead of network interface names. A backport to 2.0(.8) is also available. As a workaround, make sure that Polkit-1-support is enabled and limit privileges for the `org.blueman.dhcp.client` action to users that are able to run arbitrary commands as root anyway in /usr/share/polkit-1/rules.d/blueman.rules.

References:
https://github.com/blueman-project/blueman/security/advisories/GHSA-jpc9-mgw6-2xwx
https://bugs.launchpad.net/ubuntu/+source/blueman/+bug/1897287
https://github.com/blueman-project/blueman/releases/tag/2.1.4

Comment 1 Guilherme de Almeida Suckevicz 2020-10-28 18:52:41 UTC

Created blueman tracking bugs for this issue:

Affects: fedora-all [bug 1892437]

Comment 2 Product Security DevOps Team 2020-10-28 20:21:35 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.