Bug 1221178 (CVE-2015-4142)

Summary:	CVE-2015-4142 wpa_supplicant and hostapd: integer underflow in AP mode WMM Action frame processing
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dcbw, linville, negativo17, rkhan
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	wpa_supplicant 2.5, hostapd 2.5	Doc Type:	Bug Fix
Doc Text:	An integer underflow flaw, leading to a buffer over-read, was found in the way wpa_supplicant handled WMM Action frames. A specially crafted frame could possibly allow an attacker within Wi-Fi radio range to cause wpa_supplicant to crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-07-22 08:38:25 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:	1221552, 1221553, 1221554, 1221555, 1222015, 1222016, 1226396
Bug Blocks:	1193283, 1211193, 1219461

Description Martin Prpič 2015-05-13 12:37:28 UTC

The following flaw was found in wpa_supplicant:

A vulnerability was found in WMM Action frame processing in a case where hostapd or wpa_supplicant is used to implement AP mode MLME/SME functionality (i.e., Host AP driver of a mac80211-based driver on Linux).

The AP mode WMM Action frame parser in hostapd/wpa_supplicant goes through the variable length information element part with the length of this area calculated by removing the header length from the total length of the frame. The frame length is previously verified to be large enough to include the IEEE 802.11 header, but the couple of additional bytes after this header are not explicitly verified and as a result of this, there may be an integer underflow that results in the signed integer variable storing the length becoming negative. This negative value is then interpreted as a very large unsigned integer length when parsing the information elements. This results in a buffer read overflow and process termination.

This vulnerability can be used to perform denial of service attacks by an attacker that is within radio range of the AP that uses hostapd of wpa_supplicant for MLME/SME operations.

Vulnerable versions/configurations

hostapd v0.5.5-v2.4 with CONFIG_DRIVER_HOSTAP=y or CONFIG_DRIVER_NL80211=y in the build configuration (hostapd/.config).

wpa_supplicant v0.7.0-v2.4 with CONFIG_AP=y or CONFIG_P2P=y and CONFIG_DRIVER_HOSTAP=y or CONFIG_DRIVER_NL80211=y in the build configuration (wpa_supplicant/.config) and AP (including P2P GO) mode used at runtime.

Upstream patch:

http://w1.fi/security/2015-3/

Possible workarounds:

- wpa_supplicant: Do not enable AP mode or P2P GO operation at runtime

CVE request:

http://seclists.org/oss-sec/2015/q2/397

External References:

http://w1.fi/security/2015-3/integer-underflow-in-ap-mode-wmm-action-frame.txt

Comment 1 Tomas Hoger 2015-05-14 09:05:41 UTC

Upstream commit:

http://w1.fi/cgit/hostap/commit/?id=ef566a4d4f74022e1fdb0a2addfe81e6de9f4aae

Affected code does not exist in wpa_supplicant packages in Red Hat Enterprise Linux 5 and earlier.  The wpa_supplicant packages in Red Hat Enterprise Linux 6 and 7 contain affected code and built with require configuration option.  However, this only affects less common wpa_supplicant configurations.

Comment 2 Tomas Hoger 2015-05-14 10:55:58 UTC

Created hostapd tracking bugs for this issue:

Affects: fedora-all [bug 1221553]
Affects: epel-6 [bug 1221554]
Affects: epel-7 [bug 1221555]

Comment 3 Tomas Hoger 2015-05-14 10:56:02 UTC

Created wpa_supplicant tracking bugs for this issue:

Affects: fedora-all [bug 1221552]

Comment 5 Fedora Update System 2015-05-26 03:17:08 UTC

hostapd-2.4-2.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2015-05-27 16:04:12 UTC

hostapd-2.4-2.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2015-05-27 16:27:35 UTC

hostapd-2.4-2.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2015-06-04 15:54:42 UTC

hostapd-2.4-2.el7 has been pushed to the Fedora EPEL 7 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 Fedora Update System 2015-06-04 15:58:20 UTC

hostapd-2.0-6.el6 has been pushed to the Fedora EPEL 6 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 11 errata-xmlrpc 2015-06-11 17:48:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2015:1090 https://rhn.redhat.com/errata/RHSA-2015-1090.html

Comment 12 errata-xmlrpc 2015-07-22 07:46:01 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2015:1439 https://rhn.redhat.com/errata/RHSA-2015-1439.html

Comment 14 Fedora Update System 2015-11-12 23:28:08 UTC

wpa_supplicant-2.4-6.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 15 Fedora Update System 2015-11-23 23:20:21 UTC

wpa_supplicant-2.0-17.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.

Comment 16 Fedora Update System 2015-11-24 22:24:44 UTC

wpa_supplicant-2.4-7.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.