Apache HTTP Server up to 2.4.20 mod_http2 access control

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Apache HTTP Server up to 2.4.20. It has been classified as critical. The impacted element is an unknown function of the component mod_http2. The manipulation leads to access control. This vulnerability is uniquely identified as CVE-2016-4979. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Apache HTTP Server up to 2.4.20 (Web Server). It has been rated as critical. This issue affects an unknown code block of the component mod_http2. The manipulation with an unknown input 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 advisory summarizes:

Version 2.4.17 of the Apache HTTP Server introduced an experimental feature: mod_http2 for the HTTP/2 protocol (RFC7540, previous versions were known as Google SPDY). This module is NOT compiled in by default -and- is not enabled by default, although some distribution may have chosen to do so.

The weakness was disclosed 06/05/2016 by Erki Aring as confirmed mailinglist post (Full-Disclosure). It is possible to read the advisory at seclists.org. The identification of this vulnerability is CVE-2016-4979 since 05/24/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The advisory points out:

The Apache HTTPD web server (from 2.4.18-2.4.20) did not validate a X509 client certificate correctly when experimental module for the HTTP/2 protocol is used to access a resource.

The vulnerability scanner Nessus provides a plugin with the ID 92334 (Fedora 23 : httpd (2016-e256a03791)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 86493 (Apache HTTP Server Client Certificate Authentication Bypass Vulnerability).

Upgrading to version 2.4.23 eliminates this vulnerability. It is possible to mitigate the problem by applying the configuration setting Protocols http/1.1. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (92334), SecurityFocus (BID 91566†) and SecurityTracker (ID 1036225†). The entries VDB-6090, VDB-6092, VDB-9602 and VDB-67180 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
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: 92334
Nessus Name: Fedora 23 : httpd (2016-e256a03791)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 800678
OpenVAS Name: Apache HTTP Server Security Bypass Vulnerability - Jul16
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: HTTP Server 2.4.23
Patch: github.com
Config: Protocols http/1.1

Timelineinfo

05/24/2016 🔍
06/05/2016 +12 days 🔍
06/05/2016 +0 days 🔍
06/30/2016 +25 days 🔍
07/05/2016 +5 days 🔍
07/05/2016 +0 days 🔍
07/06/2016 +1 days 🔍
07/06/2016 +0 days 🔍
07/18/2016 +12 days 🔍
09/29/2024 +2994 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: FEDORA-2016-e256a03791
Researcher: Erki Aring
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-4979 (🔍)
GCVE (CVE): GCVE-0-2016-4979
GCVE (VulDB): GCVE-100-88667
SecurityFocus: 91566 - Apache HTTP Server CVE-2016-4979 Authentication Bypass Vulnerability
SecurityTracker: 1036225

See also: 🔍

Entryinfo

Created: 07/06/2016 09:49
Updated: 09/29/2024 01:46
Changes: 07/06/2016 09:49 (71), 04/16/2019 15:11 (16), 08/26/2022 15:14 (6), 08/26/2022 15:19 (1), 09/29/2024 01:46 (16)
Complete: 🔍
Cache ID: 216::103

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