Linux Kernel up to 4.4.22 uaccess.h __get_user_asm_ex access control

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.
7.6$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 4.4.22. Affected by this vulnerability is the function __get_user_asm_ex of the file arch/x86/include/asm/uaccess.h. The manipulation results in access control. This vulnerability is reported as CVE-2016-9644. The attack requires a local approach. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 4.4.22 (Operating System). Affected is the function __get_user_asm_ex of the file arch/x86/include/asm/uaccess.h. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-264. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux kernel 4.4.22 through 4.4.28 contains extended asm statements that are incompatible with the exception table, which allows local users to obtain root access on non-SMEP platforms via a crafted application. NOTE: this vulnerability exists because of incorrect backporting of the CVE-2016-9178 patch to older kernels.

The bug was discovered 11/07/2016. The weakness was disclosed 11/28/2016 by LINUX (Website). The advisory is shared for download at openwall.com. This vulnerability is traded as CVE-2016-9644 since 11/27/2016. The attack needs to be approached locally. A authentication is necessary for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1068.

The vulnerability was handled as a non-public zero-day exploit for at least 20 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 95433 (Ubuntu 14.04 LTS : linux-lts-xenial vulnerabilities (USN-3146-2)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196642 (Ubuntu Security Notification for Linux Vulnerabilities (USN-3146-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 2 days after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (95433) and SecurityFocus (BID 94545†). The entries VDB-92733, VDB-92734 and VDB-92735 are pretty similar. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 7.8
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 95433
Nessus Name: Ubuntu 14.04 LTS : linux-lts-xenial vulnerabilities (USN-3146-2)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 802731
OpenVAS Name: Ubuntu Update for linux-lts-xenial USN-3146-2
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: 🔍

Timelineinfo

11/07/2016 🔍
11/27/2016 +20 days 🔍
11/27/2016 +0 days 🔍
11/27/2016 +0 days 🔍
11/28/2016 +1 days 🔍
11/28/2016 +0 days 🔍
11/30/2016 +2 days 🔍
12/01/2016 +1 days 🔍
10/04/2022 +2133 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: USN-3146-2
Researcher: LINUX
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-9644 (🔍)
GCVE (CVE): GCVE-0-2016-9644
GCVE (VulDB): GCVE-100-93852
SecurityFocus: 94545 - Linux Kernel CVE-2016-9644 Local Privilege Escalation Vulnerability

See also: 🔍

Entryinfo

Created: 11/28/2016 09:32
Updated: 10/04/2022 15:32
Changes: 11/28/2016 09:32 (69), 06/11/2019 10:46 (16), 10/04/2022 15:26 (3), 10/04/2022 15:32 (1)
Complete: 🔍
Cache ID: 216:9F2:103

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Are you interested in using VulDB?

Download the whitepaper to learn more about our service!