Internet Draft T. Hansen
draft-ietf-grip-user-01.txt AT&T Laboratories
Valid for six months T. Killalea
January 31, 1999
Security Expectations for Internet Service Provider Consumers
<draft-ietf-grip-user-01.txt>
Author's version: 1.7
Status of this Memo
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This memo and its companions are discussed on the GRIP working
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Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
The purpose of this document is to provide information to the gen-
eral Internet community regarding security expectations of Internet Ser-
vice Providers (ISPs).
It is not the intent of this document to define a set of require-
ments that would be appropriate for all ISPs, but rather to provide the
community with a framework for discussion of security expectations with
current and prospective service providers.
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This document is written from the perspective of the consumer.
Companion documents provide information from the ISP perspective.
1. Introduction
The purpose of this document, and its companions [RFCisp] and
[RFCsshadd], is to express the general Internet community's expectations
of Internet Service Providers (ISPs) with respect to security.
A goal is that customers could have a framework to facilitate the
discussion of security with prospective service providers; regrettably,
such a discussion rarely takes place today.
Additionally, in informing ISPs of what the community hopes and
expects of them, a further goal is to encourage ISPs to become proactive
in making security not only a priority, but something to which they
point with pride when selling their services.
This document is addressed to Internet service purchasing
decision-makers (customers).
It has been argued that vendors begin to care about security only
when prompted by customers. We hope that these documents will encourage
both parties to more readily express how much they care about security,
and that discussion between the community and its ISPs will be
increased.
Three types of customers are considered in this document: first
connectivity customers, then hosting customers, and finally co-located
customers.
1.1. Conventions Used in this Document
The key words "REQUIRED", "MUST", "MUST NOT", "SHOULD", "SHOULD
NOT", and "MAY" in this document are to be interpreted as described in
"Key words for use in RFCs to Indicate Requirement Levels" [RFC2119].
2. Incident Response
A Security Incident Response Team (SIRT) is a team that performs,
coordinates, and supports the response to security incidents that
involve sites within a defined constituency. The Internet community's
expectations of SIRTs are described in [BCP21].
2.1. ISPs and Security Incident Response Teams
Some ISPs have Security Incident Response Teams (SIRTs). However
it should not be assumed that either the ISP's connectivity customers or
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a site being attacked by a customer of that ISP can automatically avail
of the services of the ISP's SIRT. ISP SIRTs are frequently provided as
an added-cost service, with the team defining as their constituency only
those who specifically subscribe to (and perhaps pay for) Incident
Response services.
Some providers go even further and offer services such as Virtual
Private Network (VPN) and firewall management, as well as intrusion
detection for a substantial fee.
Thus it's important to determine what incident response and secu-
rity resources are available to you, and define your incident response
escalation chain BEFORE an incident occurs.
You should find out if your ISP has a SIRT, and if so what the
charter, policies and services of that team are. (This information is
best expressed using the SIRT template as shown in Appendix D of
[BCP21].)
If the ISP doesn't have a SIRT, you should find out what role, if
any, they WILL take in response to an incident. You should also find
out if there is any other SIRT whose constituency would include yourself
and to whom incidents could be reported. You may also be able to con-
tract these services from third-party companies to perform these ser-
vices on a routine or one-time basis.
2.2. Assistance with Inbound Security Incidents
When a security incident targeting one of their connectivity custo-
mers occurs, you should expect your ISP to inform you of the attack,
provide assistance to trace the attack, and collect and protect evidence
of the incident and guard against its destruction or unintentional
announcement. If the event continues, you may ask the ISP to provide
logging in order to further diagnose the problem, or to perform filter-
ing of certain types of traffic.
You should ask your ISP what information they will be able to give
out if another customer is the party attacking you to determine whether
or not their response is acceptable to you. Some providers may give
this information freely, while others will not release the identity of
the attacker without a court order.
2.3. Notification of Vulnerabilities and Reporting of Incidents
You should expect your ISP to be proactive in notifying you of
security vulnerabilities in the services they provide. In addition, as
new vulnerabilities in systems and software are discovered, they should
indicate whether their services are threatened by these risks.
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When security incidents occur that affect components of an ISP's
infrastructure, your ISP SHOULD promptly report to you:
- who is coordinating response to the incident
- the vulnerability
- how service was affected
- what is being done to respond to the incident
- whether customer data may have been compromised
- what is being done to eliminate the vulnerability
- the expected schedule for response, assuming it can be
predicted
- the trouble ticket number being used to track the incident by
the provider, or other suitable means of identifying the
incident at a later date.
2.4. Contact Information
If you need to contact someone at your ISP, you should use the
address SECURITY@your.isp.example for network security issues,
ABUSE@your.isp.example for issues relating to inappropriate public
behaviour, and NOC@your.isp.example for issues relating to network
infrastructure. ([RFC2142] states that sites (including ISPs) must
maintain these mailboxes, as well as additional mailboxes that are
defined for receiving queries and reports relating to specific ser-
vices.) Your ISP may also have web site addresses (e.g.,
http://www.your.isp.example/security/) that you may use to check for
expanded details on the above. You should also be able to find contact
information for your ISP in Whois and in the routing registry [RFC1786].
2.4.1. After Hours
You should recieve information for reaching customer support or opera-
tions personnel on a 24x7 (24 hours, 7 days per week) basis. If the ISP
does not maintain 24x7 operations (NOC, Customer Support, etc.) then
some means of reaching customer support after hours for security
incidents should be relayed to you in advance.
2.5. Communication and Authentication
You should expect your ISP to have clear policies and procedures on
the sharing of information about a security incident with you, other
ISPs or SIRTs, with law enforcement, and with the press and the general
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public. If your jurisdiction permits, you should expect to be able to
conduct such communication with your ISP over a secure channel.
3. Policies
3.1. Security Policy
You should expect your ISP to have a policy with regard to privacy,
authentication, accountability, application of security patches, availa-
bility and violations reporting.
A more detailed discussion of Security Policy can be found in the
Site Security Handbook [RFC2196].
3.2. Appropriate Use Policy
When you establish a contract with your ISP to provide connectivity
to the Internet, that contract SHOULD be governed by an Appropriate Use
Policy (AUP). The AUP SHOULD clearly identify what you may and may not
do on the various components of the system or network, including the
type of traffic allowed on the networks. The AUP should be as explicit
as possible to avoid ambiguity or misunderstanding.
The AUP should be reviewed each time you renew your contract. You
should also expect your ISP to proactively notify you as their policies
are updated.
3.3. Sanctions
You should expect the AUP to be clear in stating what sanctions
will be enforced in the event of inappropriate behaviour. You should
also expect your ISP to be forthcoming in announcing to the community
when such sanctions are imposed.
3.4. Announcement of Policies
You should expect your ISP to publish their security and appropri-
ate use policies in a public place such as their web site. This way,
the community can be aware of what the ISP considers appropriate and can
know what action to expect in the event of inappropriate behaviour.
4. Network Infrastructure
Your ISP is responsible for managing the network infrastructure of
their portion of the Internet in such a way that it is:
- reasonably resistant to known security vulnerabilities
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- not easily hijacked by attackers for use in subsequent attacks
- capable of preventing internal illegal traffic (bogus route
announcements, spoofed traffic, etc.) generated by its custo-
mers from reaching the global Internet
5. Concerns Specific to Hosting Service Customers
[Ed: this section is totally new and needs lots of work.]
If you are hosting content on your ISP, you have additional con-
cerns.
- Generally there is a separate AUP from that used for connec-
tivity customers.
- These machines may be housed in unlocked cabinets. As such,
there must be tight restrictions as to who may have access.
Electronic access control, guards, video surveillance, etc.,
are all fair game. All visitors ESPECIALLY need to be
escorted, as the potential for damage is much higher than in a
colocation situation.
- As the customer is not generally responsible for securing the
operating system or applications, there needs to be a
heightened understanding of how the ISP reacts.
- If you also get connectivity from the ISP (i.e., a T1), you
should check to see if security for the managed site is done
by a different group and check to see if the procedures for
reporting and notification are much different.
- A modality for backups must be included, as the ISP will be
doing the majority of these. Most providers also have off-
site backup services.
- Other customers may legitimately cause a denial of service
attack by hogging all of the network capacity. Providers
should have standards as far as how saturated their networks
may get, and should prevent this from occurring.
- Cold site facilities, and hot spare hardware can be important
when recovering from an incident. Customers should inquire
with the ISP if this is important to them.
- Providers should do a good deal of proactive testing against,
and active patching of the OS and application loads. As these
loads tend to be the same from customer to customer, the ISP
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should be responsible in assuring host based security.
- Many providers offer a managed security service for additional
fees. Customers are encouraged to find out what is included
in the service that they are paying for, and to explore
options as far as what they can do.
- Generally there is option of whether or not the customer even
has root privs.
6. Concerns Specific to Co-location Customers
If you have co-located equipment at your ISP's facility, the physi-
cal security of the installation should be given appropriate considera-
tion. This is particularly so for co-located facilities to which people
from different organisations and with different security policies have
access. Many issues arise surrounding customer access to their co-
located equipment.
6.1. Acceptable Use Policy
The AUP for co-located customers is usually different from that used by
connectivity customers. You should inquire about the AUP.
6.2. Separated Equipment
Ideally you and each other customer SHOULD have a fully enclosed
locking 'cage', akin to a small room with walls and ceiling of heavy
wire mesh fencing, containing the racks in which their equipment is
mounted. Each customer would be allowed access to their own cage under
escort by one of the ISP's employees, by a guard, with keys or elec-
tronic access control that grant access specifically to their cage, or
some combination thereof.
This assignment of separate cages is expensive in terms of space
however, so many ISPs compromise by putting all co-located equipment
together in a single machine room, and managing the actions of escorted
customers very closely. However this may be insufficient to prevent
mishaps such as the accidental disconnection of another customer's
equipment. If a single machine room is used then the ISP SHOULD provide
separate locking cabinets for each co-location customer in preferance to
an open common area. Another alternative are cabinets which can
separate all of the facilities within the same cabinet, and have
independent locking mechanisms for each portion of the rack.
You should expect to always be supervised while in the physical
presence of any equipment that is not yours, and should not expect to be
allowed to touch, photograph, or examine equipment belonging to another
customer.
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6.3. Layer 1 Security
Also of importance is "layer 1" security of co-located equipment.
Other customers should not blow the same fuse that you are on by power-
ing all their machines up at once. The ISP can control this by having
separate breakers and circuits for each customer, or by overbuilding the
power system and keeping track of the power ratings of all equipment in
use.
6.4. Layer 2 Security
Also of concern is layer 2 security of co-located equipment. Your
equipment SHOULD NOT be allowed to share a physical network segment with
hosts belonging to anyone else, whether another customer or the ISP
themselves. It's common for crackers to exploit weak security or unen-
crypted remote logins on co-located customer-owned equipment to take
control of that equipment and put it into promiscuous listening mode on
the local network segment, thereby potentially compromising the privacy
and security of any other devices on that segment. The use of a switch
is generally recommended for this sort of thing.
7. References
[BCP21] Brownlee, N and E. Guttman, "Expectations for Computer
Security Incident Response", BCP 21, RFC 2350, June 1998.
[RFC1786] Bates, T., Gerich, E., Joncheray, L., Jouanigot, J-M.,
Karrenberg, D., Terpstra, M., and J. Yu, "Representation
of IP Routing Policies in a Routing Registry (ripe-
81++)", RFC 1786, March 1995.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC2142] Crocker, D., "Mailbox Names for Common Services, Roles
and Functions", RFC 2142, May 1997.
[RFC2195] Klensin, J., Catoe, R., and P. Krumviede, "IMAP/POP
AUTHorize Extension for Simple Challenge/Response", RFC
2195, September 1997.
[RFC2196] Fraser, B., "Site Security Handbook", RFC 2196, September
1997.
8. Acknowledgements
We gratefully acknowledge the constructive comments received from
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Nevil Brownlee, Randy Bush, Bill Cheswick, Barbara Y. Fraser, Randall
Gellens, Erik Guttman, Larry J. Hughes Jr., Klaus-Peter Kossakowski,
Michael A. Patton, Don Stikvoort, Bill Woodcock and Chris Kuivenhoven.
9. Security
This entire document discusses security issues.
10. Authors' Addresses
Tony Hansen
AT&T Laboratories
Lincroft, NJ 07738
USA
Phone: +1 732 576-3207
E-Mail: tony@att.com
Tom Killalea
1516 2nd Ave
Seattle, WA 98101
USA
Phone: +1 206 694-2196
E-Mail: tomk@neart.ie
11. Full Copyright Statement
Copyright (C) The Internet Society (1999). All Rights Reserved.
This document and translations of it may be copied and furnished to
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assist in its implmentation may be prepared, copied, published and dis-
tributed, in whole or in part, without restriction of any kind, provided
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dards process must be followed, or as required to translate it into
languages other than English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
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This document and the information contained herein is provided on
an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL
NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE.
This document expires August 1999.
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