nginx up to 1.11.0 ngx_files.c ngx_chain_to_iovec null pointer dereference

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.3	$0-$5k	0.00

Summaryinfo

A vulnerability identified as problematic has been detected in nginx up to 1.11.0. Impacted is the function ngx_chain_to_iovec of the file ngx_files.c. The manipulation leads to null pointer dereference. This vulnerability is traded as CVE-2016-4450. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in nginx up to 1.11.0 (Web Server) and classified as critical. This issue affects the function ngx_chain_to_iovec of the file ngx_files.c. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability.

The weakness was shared 05/31/2016 as confirmed security advisory (Mailing List). It is possible to read the advisory at mailman.nginx.org. The identification of this vulnerability is CVE-2016-4450 since 05/02/2016. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The following code is the reason for this vulnerability:

size = cl->buf->last - cl->buf->pos;

The vulnerability scanner Nessus provides a plugin with the ID 91629 (Amazon Linux AMI : nginx (ALAS-2016-715)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Amazon Linux Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 370107 (Red Hat nginx18-nginx Security Update (RHSA-2016:1425)).

Upgrading to version 1.10.1 or 1.11.1 eliminates this vulnerability. The upgrade is hosted for download at nginx.org. A possible mitigation has been published immediately after the disclosure of the vulnerability. The vulnerability will be addressed with the following lines of code:

if (ngx_buf_special(cl->buf)) {
   continue;
}

The vulnerability is also documented in the databases at Tenable (91629), SecurityFocus (BID 90967†) and SecurityTracker (ID 1036019†). The entry VDB-80760 is related to this item. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Web Server

Name

• nginx

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11.0

License

• open-source

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

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 91629
Nessus Name: Amazon Linux AMI : nginx (ALAS-2016-715)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 100533
OpenVAS Name: Ubuntu Update for nginx USN-2991-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: nginx 1.10.1/1.11.1

Timelineinfo

05/02/2016 🔍
05/31/2016 +29 days 🔍
05/31/2016 +0 days 🔍
05/31/2016 +0 days 🔍
06/02/2016 +2 days 🔍
06/03/2016 +1 days 🔍
06/07/2016 +4 days 🔍
06/16/2016 +9 days 🔍
08/22/2022 +2258 days 🔍

Sourcesinfo

Advisory: RHSA-2016:1425
Status: Confirmed

CVE: CVE-2016-4450 (🔍)
GCVE (CVE): GCVE-0-2016-4450
GCVE (VulDB): GCVE-100-87719

OVAL: 🔍

SecurityFocus: 90967 - nginx CVE-2016-4450 Denial of Service Vulnerability
SecurityTracker: 1036019

See also: 🔍

Entryinfo

Created: 06/03/2016 11:54
Updated: 08/22/2022 19:06
Changes: 06/03/2016 11:54 (73), 12/28/2018 10:55 (12), 08/22/2022 19:06 (5)
Complete: 🔍
Cache ID: 216:4F3:103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

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