CVE-2017-3141: Windows service and uninstall paths are not quoted when BIND is installed

CVE: CVE-2017-3141

Document version: 2.0

Posting date: 14 Jun 2017

Program impacted: BIND

Versions affected: 9.2.6-P2->9.2.9, 9.3.2-P1->9.3.6, 9.4.0->9.8.8, 9.9.0->9.9.10, 9.10.0->9.10.5, 9.11.0->9.11.1, 9.9.3-S1->9.9.10-S1, 9.10.5-S1

Severity: Critical

Exploitable: Locally

Description:

The BIND installer on Windows uses an unquoted service path, which can enable a local user to achieve privilege escalation if the host file system permissions allow this.

Impact:

This vulnerability exists in the installer delivered with BIND for Windows and not within BIND itself. Non-Windows builds and installations are unaffected. A manual installation of BIND where the service path is quoted when added would not be at risk.

CVSS Score: 7.2

CVSS Vector: CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H

For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H.

Workarounds:

BIND installations on Windows are not at risk if the host file permissions prevent creation of a binary in a location where the service executor would run it instead of named.exe.

Active exploits:

No known active exploits, but this generic weakness is already a well-known attack vector if user file access permissions do not adequately prevent the installation of malicious executables.

Solution: Upgrade to the patched release most closely related to your current version of BIND.  These can all be downloaded from http://www.isc.org/downloads.

• BIND 9 version 9.9.10-P1
• BIND 9 version 9.10.5-P1
• BIND 9 version 9.11.1-P1

BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers.

• BIND 9 version 9.9.10-S2
• BIND 9 version 9.10.5-S2

Acknowledgements: ISC would like to thank John Page aka hyp3rlinx for reporting this issue.

Document Revision History:

1.0 Advance Notification, 6 June 2017 1.1 Added acknowledgement, 7 June 2017 2.0 Public Announcement, 14 June 2017

Related Documents:

See our BIND 9 Security Vulnerability Matrix for a complete listing of Security Vulnerabilities and versions affected.

Do you still have questions? Questions regarding this advisory should go to security-officer@isc.org.  To report a new issue, please encrypt your message using security-officer@isc.org's PGP key which can be found here: https://www.isc.org/downloads/software-support-policy/openpgp-key/.  If you are unable to use encrypted email, you may also report new issues at: https://www.isc.org/community/report-bug/.

Note:

ISC patches only currently supported versions. When possible we indicate EOL versions affected.  (For current information on which versions are actively supported, please see https://www.isc.org/downloads/). 

ISC Security Vulnerability Disclosure Policy:

Details of our current security advisory policy and practice can be found in the ISC Software Defect and Security Vulnerability Disclosure Policy.

This Knowledgebase article is the complete and official security advisory document.

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