Linux Kernel NFSv4 Server /fs/nfsd/nfs4proc.c nfsd4_layout_verify UDP Packet array index

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

A vulnerability, which was classified as problematic, has been found in Linux Kernel (Operating System) (version now known). This issue affects the function nfsd4_layout_verify of the file /fs/nfsd/nfs4proc.c of the component NFSv4 Server. The manipulation as part of a UDP Packet leads to a array index vulnerability. Using CWE to declare the problem leads to CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. Impacted is availability.

The bug was discovered 06/27/2017. The weakness was shared 05/05/2017 by Jani Tuovila as confirmed git commit (GIT Repository). It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2017-8797 since 05/05/2017. The attack may be initiated remotely. Required for exploitation is a simple authentication. Technical details of the vulnerability are known, but there is no available exploit. The following code is the reason for this vulnerability:

if (!(exp->ex_layout_types & (1 << layout_type))) {

The vulnerability scanner Nessus provides a plugin with the ID 101233 (Virtuozzo 7 : readykernel-patch (VZA-2017-062)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Virtuozzo Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 236449 (Red Hat Update for kernel (RHSA-2017:2437)).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.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 (layout_type >= LAYOUT_TYPE_MAX ||
   !(exp->ex_layout_types & (1 << layout_type))) {

The vulnerability is also documented in the vulnerability database at Tenable (101233).

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Array index
CWE: CWE-129 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 101233
Nessus Name: Virtuozzo 7 : readykernel-patch (VZA-2017-062)
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: 🔍
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Countermeasuresinfo

Recommended: Patch
Status: 🔍

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Patch: git.kernel.org

Timelineinfo

05/05/2017 🔍
05/05/2017 +0 days 🔍
05/05/2017 +0 days 🔍
06/27/2017 +53 days 🔍
06/27/2017 +0 days 🔍
06/28/2017 +1 days 🔍
06/28/2017 +0 days 🔍
07/02/2017 +4 days 🔍
07/06/2017 +4 days 🔍
12/09/2022 +1982 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2017:1842
Researcher: Jani Tuovila
Status: Confirmed

CVE: CVE-2017-8797 (🔍)
SecurityTracker: 1038790
SecurityFocus: 99298 - Linux Kernel CVE-2017-8797 Denial of Service Vulnerability

Entryinfo

Created: 06/28/2017 21:56
Updated: 12/09/2022 13:23
Changes: 06/28/2017 21:56 (83), 10/21/2019 09:28 (4), 12/30/2020 07:50 (3), 12/09/2022 13:23 (3)
Complete: 🔍

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