QEMU Cirrus CLGD 54xx VGA Emulator out-of-bounds

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.
4.3$0-$5k0.00

Summaryinfo

A vulnerability was found in QEMU and classified as problematic. Affected by this issue is some unknown functionality of the component Cirrus CLGD 54xx VGA Emulator. Executing a manipulation can lead to out-of-bounds. This vulnerability is tracked as CVE-2018-7858. The attack is restricted to local execution. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in QEMU (Virtualization Software) (the affected version is unknown) and classified as problematic. This vulnerability affects an unknown code of the component Cirrus CLGD 54xx VGA Emulator. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. CVE summarizes:

Quick Emulator (aka QEMU), when built with the Cirrus CLGD 54xx VGA Emulator support, allows local guest OS privileged users to cause a denial of service (out-of-bounds access and QEMU process crash) by leveraging incorrect region calculation when updating VGA display.

The bug was discovered 03/09/2018. The weakness was disclosed 03/12/2018 with Citrix (oss-sec). The advisory is shared for download at openwall.com. This vulnerability was named CVE-2018-7858 since 03/08/2018. The attack needs to be approached locally. A single authentication is needed for exploitation. There are neither technical details nor an exploit publicly available.

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 $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 109894 (Ubuntu 14.04 LTS / 16.04 LTS / 17.10 / 18.04 LTS : qemu vulnerabilities (USN-3649-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 351266 (Amazon Linux Security Advisory for qemu-kvm: ALAS-2018-1034).

Upgrading eliminates this vulnerability. A possible mitigation has been published 3 months after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (109894) and SecurityFocus (BID 103350†). The entry VDB-112361 is pretty similar. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 109894
Nessus Name: Ubuntu 14.04 LTS / 16.04 LTS / 17.10 / 18.04 LTS : qemu vulnerabilities (USN-3649-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 53074
OpenVAS Name: Ubuntu Update for qemu USN-3649-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Timelineinfo

03/08/2018 🔍
03/08/2018 +0 days 🔍
03/09/2018 +1 days 🔍
03/12/2018 +3 days 🔍
03/12/2018 +0 days 🔍
03/13/2018 +1 days 🔍
05/16/2018 +64 days 🔍
05/17/2018 +1 days 🔍
02/21/2023 +1741 days 🔍

Sourcesinfo

Product: qemu.org

Advisory: USN-3649-1
Organization: Citrix
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-7858 (🔍)
GCVE (CVE): GCVE-0-2018-7858
GCVE (VulDB): GCVE-100-114412
SecurityFocus: 103350 - QEMU CVE-2018-7858 Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 03/13/2018 07:50
Updated: 02/21/2023 12:42
Changes: 03/13/2018 07:50 (74), 01/12/2020 17:39 (6), 02/21/2023 12:35 (4), 02/21/2023 12:42 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you know our Splunk app?

Download it now for free!