Security Bulletin: Multiple vulnerabilities may affect ASP.NET Core in IBM Bluemix

Summary

Vulnerabilities in .NET Core, ASP.NET Core Could Allow Elevation of Privilege. Vulnerabilities in Node.js and the c-ares library were disclosed on July 11 2017 by the Node.js Foundation. IBM SDK for Node.js has addressed the applicable CVEs.

Vulnerability Details

CVEID: CVE-2017-0256**
DESCRIPTION:** Microsoft ASP.NET Core could allow a remote attacker to conduct spoofing attacks, caused by improper validation of user supplied input.
CVSS Base Score: 6.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/125327 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)

CVEID: CVE-2017-0249**
DESCRIPTION:** Microsoft ASP.NET Core could allow a remote attacker to gain elevated privileges on the system, caused by improper validation of user supplied input.
CVSS Base Score: 8.4
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/125299 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID: CVE-2017-0247**
DESCRIPTION:** Microsoft ASP.NET Core is vulnerable to a denial of service, caused by improper validation of web requests in the TextEncoder.EncodeCore function. By inserting specially-crafted content into any system using the function to encode content, a remote attacker could exploit this vulnerability to prevent any page delivering the content from loading.
CVSS Base Score: 3.6
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/125297 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:L)

CVEID: CVE-2017-1000381**
DESCRIPTION:** c-ares could allow a remote attacker to obtain sensitive information, caused by an out-of-bounds read in the ares_parse_naptr_reply() function when parsing NAPTR responses. By sending specially crafted DNS response packet, an attacker could exploit this vulnerability to read memory outside of the given input buffer and cause a denial of service.
CVSS Base Score: 6.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/128625 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L)

CVEID: CVE-2017-11499**
DESCRIPTION:** Node.js is vulnerable to a denial of service, caused by a flaw related to constant HashTable seeds. A remote attacker could exploit this vulnerability to flood the hash and cause a denial of service.
CVSS Base Score: 7.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/129465 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

These vulnerabilities affect ASP.NET Core in IBM Bluemix v1.0.20 and earlier releases.

You can also find this file through the command-line Cloud Foundry client by running the following command:

cf ssh <appname> -c cat staging_info.yml

Look for the following lines:
{“detected_buildpack”:“ASP.NET Core (buildpack-v1.xxx)”,“start_command”:"cd . \u0026\u0026 dotnet dotnetstarter.dll --server.urls http://0.0.0.0:${PORT}"}

If the buildpack version is not at least v1.0.22 your application may be vulnerable.

Remediation/Fixes

You will need to restage (or re-push) your application using the ASP.NET Core Buildpack v1.0.22.

Workarounds and Mitigations

None.

Monitor IBM Cloud Status for Future Security Bulletins

Monitor the security notifications on the IBM Cloud Status page to be advised of future security bulletins.

References

Complete CVSS v2 Guide
On-line Calculator v2

Complete CVSS v3 Guide
On-line Calculator v3

Off

Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Change History

August 17 2017: Original version published

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an “industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response.” IBM PROVIDES THE CVSS SCORES ““AS IS”” WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. “Affected Products and Versions” referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

[{“Product”:{“code”:“HWQQQ”,“label”:“PRODUCT NOT FOUND”},“Business Unit”:{“code”:“BU055”,“label”:“Cognitive Applications”},“Component”:“Not Applicable”,“Platform”:[{“code”:“PF025”,“label”:“Platform Independent”}],“Version”:“Version Independent”,“Edition”:“”,“Line of Business”:{“code”:“”,“label”:“”}}]