Apache HTTP Server up to 2.2.31/2.4.23 mod_userdir HTTP Response Splitting crlf injection

CVSS Meta Temp Score
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CTI Interest Score
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6.4$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Apache HTTP Server up to 2.2.31/2.4.23. This affects an unknown function of the component mod_userdir. Performing a manipulation results in crlf injection (HTTP Response Splitting). This vulnerability is cataloged as CVE-2016-4975. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Apache HTTP Server up to 2.2.31/2.4.23 (Web Server). This affects an unknown code of the component mod_userdir. The manipulation with an unknown input leads to a crlf injection vulnerability (HTTP Response Splitting). CWE is classifying the issue as CWE-93. The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Possible CRLF injection allowing HTTP response splitting attacks for sites which use mod_userdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected 2.4.1-2.4.23). Fixed in Apache HTTP Server 2.2.32 (Affected 2.2.0-2.2.31).

The bug was discovered 08/14/2018. The weakness was shared 08/14/2018 (Website). The advisory is shared at httpd.apache.org. This vulnerability is uniquely identified as CVE-2016-4975 since 05/24/2016. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 112199 (SUSE SLES12 Security Update : apache2 (SUSE-SU-2018:2554-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171497 (SUSE Enterprise Linux Security Update for apache2 (SUSE-SU-2018:2815-1)).

Upgrading to version 2.2.32 or 2.4.25 eliminates this vulnerability. A possible mitigation has been published 3 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (112199) and SecurityFocus (BID 105093†). The entry VDB-94625 is related to this item. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.7
VulDB Meta Temp Score: 6.6

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.1
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Name: HTTP Response Splitting
Class: Crlf injection / HTTP Response Splitting
CWE: CWE-93 / CWE-74 / CWE-707
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: 112199
Nessus Name: SUSE SLES12 Security Update : apache2 (SUSE-SU-2018:2554-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: HTTP Server 2.2.32/2.4.25

Timelineinfo

05/24/2016 🔍
08/14/2018 +812 days 🔍
08/14/2018 +0 days 🔍
08/14/2018 +0 days 🔍
08/14/2018 +0 days 🔍
08/15/2018 +1 days 🔍
08/30/2018 +15 days 🔍
08/31/2018 +1 days 🔍
03/15/2020 +562 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: httpd.apache.org
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-4975 (🔍)
GCVE (CVE): GCVE-0-2016-4975
GCVE (VulDB): GCVE-100-122889
SecurityFocus: 105093 - Apache HTTP Server CVE-2016-4975 HTTP Response Splitting Vulnerability

See also: 🔍

Entryinfo

Created: 08/15/2018 06:39
Updated: 03/15/2020 16:11
Changes: 08/15/2018 06:39 (76), 03/15/2020 16:11 (5)
Complete: 🔍
Cache ID: 216::103

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

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