Linux/FreeBSD/Xen Intel Architecture Development 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.
6.4$0-$5k0.00

A vulnerability classified as critical has been found in Linux, FreeBSD and Xen (Operating System) (affected version not known). This affects some unknown functionality of the component Intel Architecture Development. 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. The summary by CVE is:

A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in some Xen configurations or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.

The bug was discovered 05/08/2018. The weakness was released 05/08/2018 by Jann Horn with Google Project Zero (Website). The advisory is shared at securityfocus.com. This vulnerability is uniquely identified as CVE-2018-8897 since 03/21/2018. An attack has to be approached locally. No form of authentication is needed for exploitation. Technical details are unknown but a public exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

The exploit is shared for download at exploit-db.com. It is declared as highly functional. The vulnerability scanner Nessus provides a plugin with the ID 109610 (KB4103726: Windows Server 2012 May 2018 Security Update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 390158 (Oracle VM Server for x86 Security Update for xen (OVMSA-2018-0272)).

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

The vulnerability is also documented in the databases at Tenable (109610) and Exploit-DB (44697). Entries connected to this vulnerability are available at 113918, 113919, 117442 and 117443.

Productinfo

Type

Name

License

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: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
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
ATT&CK: T1068

Local: Yes
Remote: No

Availability: 🔍
Access: Public
Status: Highly functional
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Dayunlockunlockunlockunlock
Todayunlockunlockunlockunlock

Nessus ID: 109610
Nessus Name: KB4103726: Windows Server 2012 May 2018 Security Update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 52254
OpenVAS Name: Microsoft Windows Multiple Vulnerabilities (KB4103725)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: mov_ss.rb
MetaSploit Name: Microsoft Windows POP/MOV SS Local Privilege Elevation Vulnerability
MetaSploit File: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Patch: git.kernel.org

Timelineinfo

02/27/2018 🔍
03/21/2018 +22 days 🔍
05/08/2018 +48 days 🔍
05/08/2018 +0 days 🔍
05/08/2018 +0 days 🔍
05/08/2018 +0 days 🔍
05/08/2018 +0 days 🔍
05/09/2018 +1 days 🔍
03/08/2023 +1764 days 🔍

Sourcesinfo

Advisory: RHSA-2018:1318
Researcher: Jann Horn
Organization: Google Project Zero
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-8897 (🔍)
OVAL: 🔍

SecurityTracker: 1040744
SecurityFocus: 103174 - Xen 'xen/common/memory.c' Denial of Service vulnerability

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

Entryinfo

Created: 05/09/2018 10:39
Updated: 03/08/2023 21:44
Changes: 05/09/2018 10:39 (62), 02/03/2020 08:45 (26), 03/08/2023 21:44 (6)
Complete: 🔍

Discussion

No comments yet. Languages: en.

Please log in to comment.

Do you know our Splunk app?

Download it now for free!