Linux Kernel up to 4.18.8 mm/vmacache.c vmacache_flush_all use after free

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.
6.3	$0-$5k	0.00

A vulnerability was found in Linux Kernel up to 4.18.8 (Operating System). It has been rated as critical. Affected by this issue is the function vmacache_flush_all of the file mm/vmacache.c. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An issue was discovered in the Linux kernel through 4.18.8. The vmacache_flush_all function in mm/vmacache.c mishandles sequence number overflows. An attacker can trigger a use-after-free (and possibly gain privileges) via certain thread creation, map, unmap, invalidation, and dereference operations.

The bug was discovered 09/18/2018. The weakness was disclosed 09/19/2018 by Jann Horn with Google Project Zero (Website). The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2018-17182 since 09/19/2018. The exploitation is known to be easy. Local access is required to approach this attack. No form of authentication is required for exploitation. Technical details as well as a public exploit are known.

The exploit is available at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 117720 (Fedora 27 : kernel / kernel-headers (2018-d77cc41f35)), 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 157862 (Oracle Enterprise Linux Security Update for Unbreakable Enterprise kernel (ELSA-2018-4270)).

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

The vulnerability is also documented in the databases at Tenable (117720) and Exploit-DB (45497). The entries 122244, 122245, 124953 and 130430 are pretty similar.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

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: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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unlock	unlock	unlock	unlock	unlock	unlock
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VulDB Base Score: 🔍
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Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Nessus ID: 117720
Nessus Name: Fedora 27 : kernel / kernel-headers (2018-d77cc41f35)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Patch: git.kernel.org

Timelineinfo

09/13/2018 🔍
09/18/2018 +5 days 🔍
09/19/2018 +0 days 🔍
09/19/2018 +0 days 🔍
09/19/2018 +0 days 🔍
09/20/2018 +1 days 🔍
09/26/2018 +6 days 🔍
09/27/2018 +1 days 🔍
05/17/2023 +1693 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: FEDORA-2018-d77cc41f35
Researcher: Jann Horn
Organization: Google Project Zero
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-17182 (🔍)
OVAL: 🔍

SecurityTracker: 1041748
SecurityFocus: 105417 - Linux Kernel 'mm/vmacache.c' Local Privilege Escalation Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 09/20/2018 08:18
Updated: 05/17/2023 09:46
Changes: 09/20/2018 08:18 (78), 03/25/2020 12:05 (11), 05/17/2023 09:45 (6), 05/17/2023 09:46 (1)
Complete: 🔍