Xen up to 4.11.x on x86 null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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7.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Xen up to 4.11.x on x86. Affected by this issue is some unknown functionality. Such manipulation leads to null pointer dereference. This vulnerability is referenced as CVE-2018-18883. The attack can only be performed from a local environment. No exploit is available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Xen up to 4.11.x on x86 (Virtualization Software). Affected by this issue is some unknown functionality. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to 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. Impacted is availability. CVE summarizes:

An issue was discovered in Xen 4.9.x through 4.11.x, on Intel x86 platforms, allowing x86 HVM and PVH guests to cause a host OS denial of service (NULL pointer dereference) or possibly have unspecified other impact because nested VT-x is not properly restricted.

The bug was discovered 10/24/2018. The weakness was published 10/31/2018 with Citrix (Website). The advisory is shared for download at xenbits.xen.org. This vulnerability is handled as CVE-2018-18883 since 10/30/2018. The exploitation is known to be easy. The attack needs to be approached locally. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 118570 (Xen Project Nested VT-x Instruction Guest-to-Host DoS (XSA-278)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Misc. and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171766 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2018:4070-1)).

Applying a patch is able to eliminate this problem. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (118570) and SecurityFocus (BID 105817†). Similar entries are available at VDB-127713, VDB-127714, VDB-127717 and VDB-127718. Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.5

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 118570
Nessus Name: Xen Project Nested VT-x Instruction Guest-to-Host DoS (XSA-278)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Timelineinfo

10/24/2018 🔍
10/24/2018 +0 days 🔍
10/30/2018 +6 days 🔍
10/31/2018 +0 days 🔍
10/31/2018 +0 days 🔍
10/31/2018 +0 days 🔍
10/31/2018 +0 days 🔍
11/01/2018 +0 days 🔍
06/04/2023 +1676 days 🔍

Sourcesinfo

Advisory: xenbits.xen.org
Organization: Citrix
Status: Confirmed

CVE: CVE-2018-18883 (🔍)
GCVE (CVE): GCVE-0-2018-18883
GCVE (VulDB): GCVE-100-126380
SecurityFocus: 105817 - Xen 'vmx.c' Denial of Service Vulnerability
SecurityTracker: 1042021

See also: 🔍

Entryinfo

Created: 11/01/2018 07:18
Updated: 06/04/2023 09:44
Changes: 11/01/2018 07:18 (70), 04/09/2020 14:07 (6), 06/04/2023 09:44 (4)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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