HTTP CONNECT and 407 Proxy Authentication Required messages are not integrity protected
Original Release date: 15 Aug 2016 | Last revised: 15 Aug 2016

Overview
HTTP CONNECT requests and 407 Proxy Authentication Required messages are not integrity protected and are susceptible to man-in-the-middle attacks. WebKit-based applications are additionally vulnerable to arbitrary HTML markup and JavaScript execution in the context of the originally requested domain.

Description

Web browsers and operating systems making a HTTPS request via a proxy server are vulnerable to man-in-the-middle (MITM) attacks against HTTP CONNECT requests and proxy response messages. HTTP CONNECT requests are made in clear text over HTTP, meaning an attacker in the position to modify proxy traffic may force the use of 407 Proxy Authentication Required responses to phish for credentials.
WebKit-based clients are vulnerable to additional vectors due to the fact that HTML markup and JavaScript are rendered by the client Document Object Model (DOM) in the context of the originally requested HTTPS domain.For more information, refer to the FalseCONNECT website.

Impact

An attacker in the position to control HTTP CONNECT requests and proxy responses can conduct MITM attacks, which may include credential phishing and, where vulnerable WebKit-based clients are involved, arbitrary HTML and JavaScript injection.

Solution

Apply an updateCheck with affected software vendors and apply an update, if available.

Those unable or unwilling to apply an update should consider the following workarounds.

Avoid untrusted networksAvoid using proxy-configured clients while connected to untrusted networks, including public WiFi. Using a proxy-configured client on an untrusted network increases the chance of falling victim to a MITM attack.Disable proxy configuration settingsIf use of proxy auto-configuration (PAC) or web proxy auto-discovery (WPAD) is not required, consider disabling them.

Vendor Information (Learn More)
Vendor
Status
Date Notified
Date Updated
Apple
Affected
17 Jun 2016
11 Aug 2016
Microsoft Corporation
Affected
17 Jun 2016
11 Aug 2016
Opera
Affected
17 Jun 2016
11 Aug 2016
Oracle Corporation
Affected
17 Jun 2016
11 Aug 2016
Lenovo
Not Affected
17 Jun 2016
01 Aug 2016
Arista Networks, Inc.
Unknown
17 Jun 2016
17 Jun 2016
Belkin, Inc.
Unknown
28 Jul 2016
28 Jul 2016
CentOS
Unknown
17 Jun 2016
17 Jun 2016
Cisco
Unknown
28 Jul 2016
28 Jul 2016
CoreOS
Unknown
17 Jun 2016
17 Jun 2016
Debian GNU/Linux
Unknown
17 Jun 2016
17 Jun 2016
DesktopBSD
Unknown
17 Jun 2016
17 Jun 2016
DragonFly BSD Project
Unknown
17 Jun 2016
17 Jun 2016
EMC Corporation
Unknown
17 Jun 2016
17 Jun 2016
F5 Networks, Inc.
Unknown
17 Jun 2016
17 Jun 2016
If you are a vendor and your product is affected, let us know.View More »CVSS Metrics (Learn More)
Group
Score
Vector
Base
4.3
AV:A/AC:M/Au:N/C:P/I:P/A:N
Temporal
3.4
E:POC/RL:OF/RC:C
Environmental
3.4
CDP:ND/TD:H/CR:ND/IR:ND/AR:ND

References

Credit
Thanks to Jerry Decime for reporting these vulnerabilities.
This document was written by Joel Land.

Other Information
CVE IDs: Unknown
Date Public: 15 Aug 2016
Date First Published: 15 Aug 2016
Date Last Updated: 15 Aug 2016
Document Revision: 23

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