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.
5.4	$0-$5k	0.00

A vulnerability was found in Linux Kernel up to 4.4.1 (Operating System). It has been declared as problematic. Affected by this vulnerability is the function lrw_crypt of the file crypto/algif_skcipher.c. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect availability. The summary by CVE is:

crypto/algif_skcipher.c in the Linux kernel before 4.4.2 does not verify that a setkey operation has been performed on an AF_ALG socket before an accept system call is processed, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via a crafted application that does not supply a key, related to the lrw_crypt function in crypto/lrw.c.

The bug was discovered 10/03/2016. The weakness was released 11/28/2016 (Website). The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2015-8970 since 11/04/2016. The exploitation appears to be easy. An attack has to be approached locally. Required for exploitation is a single authentication. Technical details are known, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 55 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 102734 (CentOS 7 : kernel (CESA-2017:1842) (Stack Clash)), 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 169979 (SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2017:1301-1)).

Upgrading to version 4.4.2 eliminates this vulnerability. A possible mitigation has been published 10 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (102734). Entries connected to this vulnerability are available at 94697 and 97620.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.4.0
• 4.4.1

License

• open-source

CPE 2.3info

• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

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

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
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: 🔍

Local: Yes
Remote: No

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: 102734
Nessus Name: CentOS 7 : kernel (CESA-2017:1842) (Stack Clash)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 871165
OpenVAS Name: RedHat Update for kernel RHSA-2017:1842-01
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: Kernel 4.4.2
Patch: git.kernel.org

Timelineinfo

10/03/2016 🔍
11/04/2016 +32 days 🔍
11/10/2016 +6 days 🔍
11/27/2016 +17 days 🔍
11/28/2016 +1 days 🔍
11/28/2016 +0 days 🔍
08/23/2017 +268 days 🔍
08/25/2017 +2 days 🔍
10/04/2022 +1866 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2017:1842
Status: Not defined
Confirmation: 🔍

CVE: CVE-2015-8970 (🔍)
SecurityFocus: 94217 - Linux Kernel 'crypto/lrw.c' Local Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 11/28/2016 09:31
Updated: 10/04/2022 14:26
Changes: 11/28/2016 09:31 (70), 06/11/2019 09:47 (14), 10/04/2022 14:26 (4)
Complete: 🔍

Discussion

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