Httpoxy issue in apache2 (Alpine package)

1) Httpoxy issue

EUVDB-ID: #VU337

Risk: Medium

CVSSv3.1: 7.3 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-5387

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information and compromise vulnerable server.

The vulnerability exists due to a design error in multiple implementations of web servers. A remote unauthenticated attacker can use a specially crafted Proxy header in HTTP request to influence HTTP_PROXY environment variable and redirect application’s HTTP traffic to arbitrary proxy server.

Successful exploitation of this vulnerability may allow an attacker to gain unauthorized access to sensitive information and compromise vulnerable server.

This vulnerability is known as httppoxy.

Mitigation

Install update from vendor's website.

Vulnerable software versions

apache2 (Alpine package): 2.2.20-r0 - 2.4.16-r0

External links

http://git.alpinelinux.org/aports/commit/?id=57ba71e0786da6d5383c4785fb65be50a2cad693
http://git.alpinelinux.org/aports/commit/?id=99de0bab9d739108d84a5f31ac83a8357372ef30
http://git.alpinelinux.org/aports/commit/?id=23afbfbed72efa68c1ea62b837270f16535a1c33
http://git.alpinelinux.org/aports/commit/?id=e82b1d4b8ffc69d3b596fcd2fbad9d51f3da9084
http://git.alpinelinux.org/aports/commit/?id=fb231f9f106b55bd799d863c5e761f1c0843bd4d
http://git.alpinelinux.org/aports/commit/?id=b7f662b790f7f1998f8cf656d8b9e5abc0964f68

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.