A vulnerability was found in Xen up to 4.9.x (Virtualization Software). It has been rated as problematic. This issue affects some unknown processing of the component Memory Comparison. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. The summary by CVE is:

An issue was discovered in Xen 4.5.x through 4.9.x allowing attackers (who control a stub domain kernel or tool stack) to cause a denial of service (host OS crash) because of a missing comparison (of range start to range end) within the DMOP map/unmap implementation.

The bug was discovered 10/12/2017. The weakness was released 10/18/2017 as XSA-238 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. The identification of this vulnerability is CVE-2017-15591 since 10/18/2017. The exploitation is known to be easy. An attack has to be approached locally. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 6 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 104085 (openSUSE Security Update : xen (openSUSE-2017-1181)), 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 170438 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2017:2864-1)).

Applying a 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 (104085). Entries connected to this vulnerability are available at 98144, 107979, 107980 and 107982.

Productinfo

Type

• Virtualization Software

Name

• Xen

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9

License

• open-source

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CPE 2.2info

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