Xen pygrub Validator input validation

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Xen. This vulnerability affects unknown code of the component pygrub Validator. This manipulation causes input validation. This vulnerability is handled as CVE-2016-9380. It is possible to launch the attack on the local host. There is not any exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability has been found in Xen (Virtualization Software) (the affected version is unknown) and classified as critical. Affected by this vulnerability is an unknown code of the component pygrub Validator. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The pygrub boot loader emulator in Xen, when nul-delimited output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via NUL bytes in the bootloader configuration file.

The bug was discovered 11/22/2016. The weakness was released 11/22/2016 by Daniel Richman and Gabor Szarka as XSA-198 as confirmed security advisory (Website). It is possible to read the advisory at xenbits.xen.org. The public release was coordinated with the project team. This vulnerability is known as CVE-2016-9380 since 11/17/2016. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 900047 , which helps to determine the existence of the flaw in a target environment. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276244 (Fedora Security Update for xen (FEDORA-2016-999e1a6927)).

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 databases at Tenable (900047), SecurityFocus (BID 94473†) and SecurityTracker (ID 1037347†). Entries connected to this vulnerability are available at VDB-92454, VDB-92455, VDB-92462 and VDB-93307. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 900047
Nessus File: 🔍

OpenVAS ID: 703729
OpenVAS Name: Debian Security Advisory DSA 3729-1 (xen - security update)
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

11/17/2016 🔍
11/22/2016 +5 days 🔍
11/22/2016 +0 days 🔍
11/22/2016 +0 days 🔍
11/22/2016 +0 days 🔍
11/25/2016 +3 days 🔍
11/25/2016 +0 days 🔍
01/23/2017 +59 days 🔍
05/14/2026 +3398 days 🔍

Sourcesinfo

Advisory: XSA-198
Researcher: Daniel Richman, Gabor Szarka
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-9380 (🔍)
GCVE (CVE): GCVE-0-2016-9380
GCVE (VulDB): GCVE-100-93811

OVAL: 🔍

SecurityFocus: 94473 - Xen PyGrub Multiple Privilege Escalation Vulnerabilities
SecurityTracker: 1037347

See also: 🔍

Entryinfo

Created: 11/25/2016 11:57
Updated: 05/14/2026 16:49
Changes: 11/25/2016 11:57 (67), 06/10/2019 06:56 (13), 05/14/2026 16:49 (17)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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