Linux Kernel cleancache Subsystem information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel. It has been rated as problematic. Affected by this vulnerability is an unknown functionality of the component cleancache Subsystem. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2018-16862. Local access is required to approach this attack. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel (Operating System) (version unknown). This issue affects an unknown function of the component cleancache Subsystem. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

A security flaw was found in the Linux kernel in a way that the cleancache subsystem clears an inode after the final file truncation (removal). The new file created with the same inode may contain leftover pages from cleancache and the old file data instead of the new one.

The bug was discovered 11/23/2018. The weakness was disclosed 11/26/2018 by ERNE as confirmed mailinglist post (oss-sec). It is possible to read the advisory at seclists.org. The identification of this vulnerability is CVE-2018-16862 since 09/11/2018. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 3 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 119813 (Amazon Linux AMI : kernel (ALAS-2018-1133)), 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 351457 (Amazon Linux Security Advisory for kernel: ALAS-2018-1133).

Upgrading eliminates this vulnerability. A possible mitigation has been published 4 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (119813) and SecurityFocus (BID 106009†). The entries VDB-122231, VDB-122230, VDB-122325 and VDB-127051 are pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
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: 🔍

CNA Base Score: 5.3
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 119813
Nessus Name: Amazon Linux AMI : kernel (ALAS-2018-1133)
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: 🔍

Timelineinfo

09/11/2018 🔍
11/23/2018 +73 days 🔍
11/24/2018 +1 days 🔍
11/26/2018 +2 days 🔍
11/26/2018 +0 days 🔍
11/27/2018 +1 days 🔍
12/20/2018 +23 days 🔍
12/21/2018 +1 days 🔍
06/11/2023 +1633 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: USN-3879-1
Researcher: ERNE
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-16862 (🔍)
GCVE (CVE): GCVE-0-2018-16862
GCVE (VulDB): GCVE-100-127127
SecurityFocus: 106009 - Linux Kernel CVE-2018-16862 Local Security Bypass Vulnerability

See also: 🔍

Entryinfo

Created: 11/27/2018 09:31
Updated: 06/11/2023 14:10
Changes: 11/27/2018 09:31 (75), 04/14/2020 20:57 (6), 06/11/2023 14:08 (4), 06/11/2023 14:10 (11)
Complete: 🔍
Cache ID: 216::103

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