Linux Foundation Xen up to 4.3.1 on Intel VT-d IOMMU TLB Flush 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.
3.8$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Linux Foundation Xen up to 4.3.1 on Intel VT-d. Affected by this issue is some unknown functionality of the component IOMMU TLB Flush Handler. Such manipulation leads to access control. This vulnerability is traded as CVE-2013-6400. There is no exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in Linux Foundation Xen up to 4.3.1 on Intel VT-d (Virtualization Software). It has been rated as problematic. Affected by this issue is an unknown functionality of the component IOMMU TLB Flush Handler. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality. CVE summarizes:

Xen 4.2.x and 4.3.x, when using Intel VT-d and a PCI device has been assigned, does not clear the flag that suppresses IOMMU TLB flushes when unspecified errors occur, which causes the TLB entries to not be flushed and allows local guest administrators to cause a denial of service (host crash) or gain privileges via unspecified vectors.

The weakness was shared 12/10/2013 by Jan Beulich with SuSE as XSA-80 as confirmed mailinglist post (oss-sec). The advisory is available at seclists.org. This vulnerability is handled as CVE-2013-6400 since 11/04/2013. Local access is required to approach this attack. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1068 by the MITRE ATT&CK project. The advisory points out:

An internal flag is used to temporarily suppress IOMMU TLB flushes, in order to consolidate multiple single page flushes into one wider flush. This flag is not cleared again, on certain error paths. This can result in TLB flushes not happening when they are needed. Retaining stale TLB entries could allow guests access to memory that ought to have been revoked, or grant greater access than intended.

The vulnerability scanner Nessus provides a plugin with the ID 71634 (Fedora 18 : xen-4.2.3-12.fc18 (2013-23466)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 166934 (OpenSuSE Security Update for xen (openSUSE-SU-2014:0482-1)).

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability. The mailinglist post contains the following remark:

Xen 4.1.x and earlier are not vulnerable. This issue can be avoided by not assigning PCI devices to untrusted guests on systems supporting Intel VT-d.

The vulnerability is also documented in the databases at Tenable (71634), SecurityFocus (BID 64195†), OSVDB (100830†), Secunia (SA55932†) and Vulnerability Center (SBV-42524†). The entries VDB-9744 and VDB-11330 are related to this item. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.8

VulDB Base Score: 4.0
VulDB Temp Score: 3.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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

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

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 71634
Nessus Name: Fedora 18 : xen-4.2.3-12.fc18 (2013-23466)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
Nessus Port: 🔍

OpenVAS ID: 867199
OpenVAS Name: Fedora Update for xen FEDORA-2013-23457
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

11/04/2013 🔍
12/10/2013 +36 days 🔍
12/10/2013 +0 days 🔍
12/10/2013 +0 days 🔍
12/10/2013 +0 days 🔍
12/10/2013 +0 days 🔍
12/11/2013 +1 days 🔍
12/12/2013 +1 days 🔍
12/13/2013 +1 days 🔍
12/26/2013 +13 days 🔍
06/04/2021 +2717 days 🔍

Sourcesinfo

Vendor: linuxfoundation.org

Advisory: XSA-80
Researcher: Jan Beulich
Organization: SuSE
Status: Confirmed

CVE: CVE-2013-6400 (🔍)
GCVE (CVE): GCVE-0-2013-6400
GCVE (VulDB): GCVE-100-11474

OVAL: 🔍

SecurityFocus: 64195 - Xen IOMMU TLB Flushing Suppress Flag Privilege Escalation Vulnerability
Secunia: 55932 - Xen IOMMU TLB Flushing Suppress Flag Privilege Escalation Vulnerability, Less Critical
OSVDB: 100830
SecurityTracker: 1029468
Vulnerability Center: 42524 - Xen 4.2 Through 4.3.1 Local Privilege Escalation and DoS Vulnerability due to a Flaw in IOMMU TLB Flushes, Medium

See also: 🔍

Entryinfo

Created: 12/12/2013 15:41
Updated: 06/04/2021 09:16
Changes: 12/12/2013 15:41 (77), 06/26/2018 08:40 (11), 06/04/2021 09:16 (3)
Complete: 🔍
Cache ID: 216:79B:103

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!