nginx RFC 3875 Namespace Conflict HTTP_PROXY access control

CVSS Meta Temp Score
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in nginx. Affected by this issue is some unknown functionality of the component RFC 3875 Namespace Conflict Handler. The manipulation of the argument HTTP_PROXY as part of Environment Variable leads to access control. This vulnerability is traded as CVE-2016-5387. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to modify the configuration settings.

Detailsinfo

A vulnerability, which was classified as critical, has been found in nginx (Web Server) (the affected version is unknown). This issue affects an unknown code of the component RFC 3875 Namespace Conflict Handler. The manipulation of the argument HTTP_PROXY as part of a Environment Variable leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality, integrity, and availability.

The weakness was shared 07/19/2016 as Mitigating the HTTPoxy Vulnerability with NGINX as confirmed advisory (Website). The advisory is shared at nginx.com. The identification of this vulnerability is CVE-2016-5387 since 06/10/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 92378 (CentOS 5 / 6 : httpd (CESA-2016:1421) (httpoxy)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CentOS Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 370348 (Apple Mac OS X Security Update Sierra 10.12.4, El Capitan 2017-001 and Yosemite 2017-001 Not Installed (APPLE-SA-2017-03-27-3)). The advisory illustrates:

A client can create arbitrary environment variables (beginning with HTTP_) in the application’s environment by sending requests with the appropriate header. For instance, the request header Foo: bar becomes the environment variable HTTP_FOO=bar.

It is possible to mitigate the problem by applying the configuration setting fastcgi_param HTTP_PROXY ""; proxy_set_header Proxy "";. A possible mitigation has been published before and not just after the disclosure of the vulnerability. Attack attempts may be identified with Snort ID 39737.

The vulnerability is also documented in the databases at Tenable (92378), SecurityFocus (BID 91816†) and SecurityTracker (ID 1036334†). forum.nginx.org is providing further details. The entries VDB-89669, VDB-93958, VDB-94625 and VDB-94626 are related to this item. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.9

VulDB Base Score: 8.1
VulDB Temp Score: 7.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.1
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 92378
Nessus Name: CentOS 5 / 6 : httpd (CESA-2016:1421) (httpoxy)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 864875
OpenVAS Name: Ubuntu Update for apache2 USN-3038-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Config
Status: 🔍

0-Day Time: 🔍

Config: fastcgi_param HTTP_PROXY ""; proxy_set_header Proxy "";

Snort ID: 39737
Snort Message: SERVER-WEBAPP HttpOxy CGI application vulnerability potential man-in-the-middle attempt
Snort Class: 🔍

Timelineinfo

06/10/2016 🔍
07/18/2016 +38 days 🔍
07/18/2016 +0 days 🔍
07/18/2016 +0 days 🔍
07/18/2016 +0 days 🔍
07/19/2016 +1 days 🔍
07/19/2016 +0 days 🔍
07/19/2016 +0 days 🔍
09/06/2022 +2240 days 🔍

Sourcesinfo

Advisory: Mitigating the HTTPoxy Vulnerability with NGINX
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-5387 (🔍)
GCVE (CVE): GCVE-0-2016-5387
GCVE (VulDB): GCVE-100-89849

OVAL: 🔍

SecurityFocus: 91816 - Apache HTTP Server CVE-2016-5387 Security Bypass Vulnerability
SecurityTracker: 1036334

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 07/19/2016 19:52
Updated: 09/06/2022 16:50
Changes: 07/19/2016 19:52 (74), 03/04/2019 08:23 (15), 09/06/2022 16:43 (3), 09/06/2022 16:50 (1)
Complete: 🔍
Cache ID: 216:CFE:103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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