Vulnerability Note VU#971035
Simple Certificate Enrollment Protocol (SCEP) does not strongly authenticate certificate requests
Simple Certificate Enrollment Protocol (SCEP) does not strongly authenticate certificate requests made by users or devices.
IETF Internet-Draft draft-nourse-scep-23 "...defines a protocol, Simple Certificate Enrollment Protocol (SCEP), for certificate management and certificate and CRL queries in a closed environment." Mobile Device Management (MDM) is defined as "...software that secures, monitors, manages and supports mobile devices deployed across mobile operators, service providers and enterprises. MDM functionality typically includes over-the-air distribution of applications, data and configuration settings for all types of mobile devices, including mobile phones, smartphones, tablet computers, ruggedized mobile computers, mobile printers, mobile POS devices, etc." Multiple MDM software packages use SCEP as a method to handle certificate management and certificate CRL queries within an organization.
When a user or a device requests a certificate, the SCEP implementation may require a challenge password. It may be possible for a user or device to take their legitimately acquired SCEP challenge password and use it to obtain a certificate that represents a different user with a higher level of access such as a network administrator, or to obtain a different type of certificate than what was intended. It is also possible for SCEP implementations or system administrators to not require the challenge password, or to share a static password across many users.
The IETF protocol suite currently includes two certificate management protocols with more comprehensive functionality: Certificate Management Protocol (CMP) [RFC4210] and Certificate Management over CMS (CMC) [RFC5272]. Environments that do not require interoperability with SCEP implementations SHOULD use the above-mentioned, PKIX-standard certificate management protocols. In light of the functionality gap between this specification [SCEP] and the two IETF standards track protocols, this specification is being published as Historic. Even when interoperability with the installed base of SCEP implementations is needed, implementers are encouraged to support one of these comprehensive standards track certificate management protocols in addition to the protocol defined in this specification.
Additional information can be found in Certified Security Solutions, Inc's The Use of the Simple Certificate Enrollment Protocol (SCEP) and Untrusted Devices whitepaper.
An attacker could elevate their permissions by requesting a certificate of a different, possibly higher privileged user that would allow them to access resources that they would not otherwise be able to access.
We are currently unaware of a practical solution to this problem.
Vendor Information (Learn More)
|Vendor||Status||Date Notified||Date Updated|
|Apple Inc.||Not Affected||12 Apr 2012||29 Jun 2012|
|Asavie Technologies Ltd||Not Affected||-||21 Sep 2012|
|Cisco Systems, Inc.||Not Affected||12 Apr 2012||29 Jun 2012|
|GlobalSign||Not Affected||-||29 Mar 2013|
|Microsoft Corporation||Not Affected||05 Apr 2012||29 Jun 2012|
|MobileIron||Not Affected||-||20 Aug 2012|
|SilverbackMDM||Not Affected||-||04 Jul 2012|
|Zenprise||Not Affected||12 Apr 2012||29 Jun 2012|
|McAfee||Unknown||12 Apr 2012||12 Apr 2012|
CVSS Metrics (Learn More)
Thanks to Ted Shorter of Certified Security Solutions for reporting this vulnerability.
This document was written by Michael Orlando and Art Manion.
- CVE IDs: Unknown
- Date Public: 27 Jun 2012
- Date First Published: 27 Jun 2012
- Date Last Updated: 14 Apr 2015
- Document Revision: 59
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