QEMU hw/9pfs/9p.c v9fs_wstat race condition

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 labeled as problematic has been found in QEMU. The impacted element is the function v9fs_wstat of the file hw/9pfs/9p.c. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2018-19489. The attack can only be performed from a local environment. No exploit is available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in QEMU (Virtualization Software) (the affected version unknown). It has been rated as problematic. Affected by this issue is the function v9fs_wstat of the file hw/9pfs/9p.c. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is availability. CVE summarizes:

v9fs_wstat in hw/9pfs/9p.c in QEMU allows guest OS users to cause a denial of service (crash) because of a race condition during file renaming.

The bug was discovered 11/26/2018. The weakness was published 12/13/2018 (oss-sec). The advisory is available at openwall.com. This vulnerability is handled as CVE-2018-19489 since 11/23/2018. The exploitation is known to be easy. Local access is required to approach this attack. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 17 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 121436 (Debian DLA-1646-1 : qemu security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172079 (SUSE Enterprise Linux Security Update for qemu (SUSE-SU-2019:0435-1)).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.qemu.org. A possible mitigation has been published 2 months after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (121436) and SecurityFocus (BID 106007†). Similar entries are available at VDB-127968, VDB-131004, VDB-131908 and VDB-132033. If you want to get best quality of vulnerability data, you may have to visit VulDB.

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: Race condition
CWE: CWE-362
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: 121436
Nessus Name: Debian DLA-1646-1 : qemu security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Patch: 1d20398694a3b67a388d955b7a945ba4aa90a8a8

Timelineinfo

11/22/2018 🔍
11/23/2018 +1 days 🔍
11/26/2018 +3 days 🔍
12/13/2018 +17 days 🔍
12/13/2018 +0 days 🔍
12/14/2018 +1 days 🔍
01/29/2019 +46 days 🔍
01/30/2019 +1 days 🔍
06/19/2023 +1601 days 🔍

Sourcesinfo

Product: qemu.org

Advisory: USN-3923-1
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-19489 (🔍)
GCVE (CVE): GCVE-0-2018-19489
GCVE (VulDB): GCVE-100-127970
X-Force: 153326
SecurityFocus: 106007 - QEMU CVE-2018-19489 Local Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 12/14/2018 09:14
Updated: 06/19/2023 09:38
Changes: 12/14/2018 09:14 (76), 04/20/2020 22:51 (4), 06/19/2023 09:35 (6), 06/19/2023 09:38 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to stay up to date on a daily basis?

Enable the mail alert feature now!