CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
3.7 | $0-$5k | 0.00 |
A vulnerability was found in XenSource Xen 4.3.x/4.4.x/4.5.x/4.6.x on AMD x86 (Virtualization Software). It has been declared as problematic. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality.
The weakness was released 03/24/2016 by Jan Beulich with SuSE as XSA-172 as confirmed security advisory (Website). The advisory is shared for download at xenbits.xen.org. This vulnerability was named CVE-2016-3159 since 03/15/2016. The attack needs to be approached locally. Required for exploitation is a single authentication. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1068. The advisory points out:
There is a workaround in Xen to deal with the fact that AMD CPUs don't load the x86 registers FIP (and possibly FCS), FDP (and possibly FDS), and FOP from memory (via XRSTOR or FXRSTOR) when there is no pending unmasked exception. (See XSA-52.) However, this workaround does not cover all possible input cases. This is because writes to the hardware FSW.ES bit, which the current workaround is based on, are ignored; instead, the CPU calculates FSW.ES from the pending exception and exception mask bits. Xen therefore needs to do the same. Note that part of said workaround was the subject of XSA-52. This can leak register contents from one guest to another. The registers in question are the FPU instruction and data pointers and opcode.
The vulnerability scanner Nessus provides a plugin with the ID 93296 (SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2016:2093-1) (Bunker Buster)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 370023 (Citrix XenServer Security Update (CTX209443)).
Applying the patch xsa172.patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.
The vulnerability is also documented in the vulnerability database at Tenable (93296).
Product
Type
Vendor
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 3.8VulDB Meta Temp Score: 3.7
VulDB Base Score: 3.8
VulDB Temp Score: 3.7
VulDB Vector: 🔍
VulDB Reliability: 🔍
NVD Base Score: 3.8
NVD Vector: 🔍
CVSSv2
AV | AC | Au | C | I | A |
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💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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unlock | unlock | unlock | unlock | unlock | unlock |
unlock | unlock | unlock | unlock | unlock | unlock |
unlock | unlock | unlock | unlock | unlock | unlock |
VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
NVD Base Score: 🔍
Exploiting
Class: Access controlCWE: CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍
Local: Yes
Remote: No
Availability: 🔍
Status: Not defined
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
0-Day | unlock | unlock | unlock | unlock |
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Today | unlock | unlock | unlock | unlock |
Nessus ID: 93296
Nessus Name: SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2016:2093-1) (Bunker Buster)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
OpenVAS ID: 867773
OpenVAS Name: Fedora Update for xen FEDORA-2016-5
OpenVAS File: 🔍
OpenVAS Family: 🔍
Qualys ID: 🔍
Qualys Name: 🔍
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: PatchStatus: 🔍
Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Patch: xsa172.patch
Timeline
03/15/2016 🔍03/24/2016 🔍
03/24/2016 🔍
03/24/2016 🔍
03/29/2016 🔍
03/31/2016 🔍
04/13/2016 🔍
04/13/2016 🔍
04/14/2016 🔍
09/02/2016 🔍
07/11/2022 🔍
Sources
Vendor: citrix.comAdvisory: XSA-172
Researcher: Jan Beulich
Organization: SuSE
Status: Confirmed
Confirmation: 🔍
CVE: CVE-2016-3159 (🔍)
OVAL: 🔍
SecurityTracker: 1035435
Vulnerability Center: 58187 - Xen 4.x arch/x86/i387.c on AMD64 Processors Local Register Content Information Disclosure Vulnerability, Low
SecurityFocus: 85716 - Xen CVE-2016-3159 Information Disclosure Vulnerability
Entry
Created: 03/31/2016 16:48Updated: 07/11/2022 17:16
Changes: 03/31/2016 16:48 (81), 02/04/2019 15:12 (13), 07/11/2022 17:16 (3)
Complete: 🔍
Cache ID: 3:740:103
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