• RiskAssessment

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• česky | english

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Prelude

This is a risk assessment based on AS/NZS 4360:2004. This is work in progress and not endorsed by CAcert board.

Context

This risk assessment applies to the CAcert operation as a certificate authority. A lot of the governance obligations of the operation as a certificate authority tie to the operation of CAcertIncorporated Association and these aspects are incorporated into this risk assessment.

Risks that are to be managed are ones that affect the viability of the CAcerts certificate authority function.

Q(iang): organistion is what? There is the CAcert Inc Association, the certificate authority, the Assurer network, sundry others and finally, the Community. If organisation as a whole, perhaps the Community, but also the CA ...

(dan) scoped to CA and to some extend addressed the governance/ community dependencies

External Context

CAcert is a community organisation that is in the business of validating identities and provides a certificate/X509 service based on this. It operates globally. Like all certification authorities (CAs) risk are ones of proper process and technology that support a high validation of identities to the owners of certificates. Reputation is highly important to CAcert.

CAcerts certificate authority obligations are dependant on the community of assurers and the Community Agreement sets a standard of mutual obligation that CAcert is determined to uphold. Unlike most CAs the split between assurance and certificate issuance creates a large obligation to serve the assurance community.

Key business goals are to gain InclusionStatus into major browsers. The Mozilla organisation has required the completion of an Audit Project to forfill its inclusion status and as such this is the major goal.

The Audit project is funded by NLnet and is under obligation to deliver outcomes at specified dates.

Internal Context

The board and management subcommittee (M-SC) are volunteers committed to these goals of the organisation. Their time however is limited. CAcert is an incorporated organisation in NSW Australia that is managed by the board. The board has deligated CEO like duties to the M-SC.

CAcert's assets include ownership of servers that provide various online functions necessary for the performance of a CA. Audit and documentation services have been contracted out as have hosting, firewall management.

CAcert's financial assets are largely funded activities dependent on delivering outcomes.

Internal goals are to enhance the system administration to a supportable level.

Risk Measurement

Risks rated above Medium will be managed. Medium risks will be managed if time/cost permits. The below consequence/likelyhood factors determine risk.

Consequence Ratings

These describe the harms that occur if the threat is realized.

• Consequence Category	Meaning
  Catastrophic	Will impact the long term viability of the organisation
  Major	Will result in CAcert's root certificate being revoked out of major browsers
  	Loss of confidentially of CAcert root private keys
  	Will result in wide scale revocation or reissuing of certificates
  	Serious damage of the reputation of CAcert's management /staff / critical systems
  	Inability to issue certificates for more that two weeks
  	Wide scale significant inconvenience to users of CAcert certificates e.g. no reading validation of CAcert signed email/ no accessability to CAcert server sites due to CRL/OCSP failure
  Moderate	Inability to issue certificates for a period less than two weeks
  	Denial of service of CRL or OCSP services greater than 5 minutes
  	Significant PR required to address failures
  	Delays to the progress of the Audit / Systems Manual
  	Unplanned costs greater that 1000 EU
  Minor	Press associated with the compromise of non-critical systems
  	Actions that require legal representation
  	Breach of confidential communications
  	Unplanned costs greater that 400 EU
  Insignificant	Unavailability of non-critical systems for less that one day
  	Need to revoke individual identity registration

(really these should be determined and signed off by management)

Q(iang): there is an interesting comment in the choice of catastrophic and major risks, which places the survival of the organisation above the CA and reliance by (explicit and implicit) parties. I do not disagree, but it is certainly a debate to be had. The choice above to some extent reflects the "wider mission" of security rather than the "narrow mission" of "free certs".

(dan): To my understanding to meet the "wider mission of security" a governance structure is required to obtain the necessary credability that is pretty mandated in the security community.

Q(iang): the recent debate over DoB was based on the threat of identity theft. recent USA-credit-market developments indicate that a large scale identity theft has rocketed from a minor risk (if covered up) to a major risk (as regulators get involved, fines are likely, wholescale revision of security is indicated, etc).

(dan) this almost leads to a risk assessment based on PR and legal risk (which is almost is anyway). I'm not sure that is such a bad thing either.

Likelihood Ratings

• Almost Certain	every day
  Likely	Once every 3 months
  Possible	Once a year
  Unlikely	Once in 5 years
  Rare	Less than once in 5 years

Risk Matrix

Risks are:

• E - Extreme
• H - High
• M - Medium
• L - Low

  Consequence
  	Insignificant	Minor	Moderate	Major	Catastrophic
  Almost Certian	H	H	E	E	E
  Likely	M	H	H	E	E
  Possible	L	M	H	E	E
  Unlikely	L	L	M	H	E
  Rare	L	L	L	M	H

Assets

Assets here are annotated with the consequence rating should the asset no longer be available.

Intangible Assets

• Meeting obligations of an included CA in Mozilla (Major)
• Incorporation Status (Moderate)
• Reputation (Major)
• Community Support e.g. Assurers willingness to assure people (Moderate)

Systems

Different assets are critical for different reasons. The below indicates which security aspect of the asset has consequences.

Critical Systems

• Asset	Confidentiality	Integrity	Availability short term	Availability long term
  Root key (RK)1	Major	Moderate	Moderate (<1 week)	Major (>1 weeks)
  signing mechanism (SM) including main website	Insignificant	Major	Moderate (<2 week)	Major (>2 weeks)
  OCSP service /CRL distribution points2,3	Insignificant	Major	Moderate (<5 minutes) or 99.9999%	Major (>5 minutes) or < 99.999%
  DNS 4	None	Major	Moderate (<5 minutes) or 99.9999%	Major (>5 minutes) or < 99.999%
  User database (UDB)	Major	Major	Minor (<24 hours)	Moderate 5 (>24 hours)
  Main website including email/domain ping testing	Minor6	Insignificant	Minor (<24 hours)	Moderate5 (>24 hours)

Non-critical systems

• Asset	Confidentiality	Integrity	Availability short Term	Availability long term
  List server (board/arbitration lists)	Moderate	Moderate	Minor <1week	Moderate >1week
  email server	Moderate	Moderate	Minor <1week	Moderate7 >1week
  Wiki	Minor (for acl pages)	Minor (for acl pages)	Minor <1week	Moderate >1week
  Blog	Insignificant	Moderate	Insignificant <2 weeks	Minor >2 weeks
  IRC	Insignificant	Insignificant	Insignificant <2 weeks	Minor >2 weeks
  SVN	Insignificant	Minor	Insignificant <2 weeks	Minor >2 weeks
  audit
  CATS	Minor	Moderate	Insignificant <2 weeks	Minor >2 weeks
  test	Insignificant	Moderate8	Insignificant <2 weeks	Minor >2 weeks
  audit

TODO find/determine the purpose of audit

Other Assets

• Financial Assets (Moderate)

• Relationships of service providers (Bit and Tunix) (Major)

• Domains (cacert.org + others(cacert.at - as significant?)) (Major)

Threats

Once inclusion into Mozilla browsers the threat profile is raised significantly. As the ability to respond to this threat is timely, this risk assessment assumes inclusion status has been obtained.

• Commercial CAs
  • CAcert's zero cost model significantly undermines the viability of other CAs business.
• Crackers
  • These are largely assumed to be financed by the commercial CAs
• Criminal Fraud Organisations
  • Issuing certificates of financial institutions will be highly profitable in phishing attacks
• Government

  • Some governments view wide scale encryption as a management threat need to map threat to legal/intelligence service objectives/priorities to address this

• Law
  • Being summonsed to court to defend a certificate issue
  • Confiscation of system assets on charges like piracy, copyright infringement
• Disgruntled staff / members

Q(iang): the above seem to be the actors, whereas the threats might be: hacking, legal (filed case, legal seizure, privacy investigation, investigation by other regulator, etc); outside theft, loss, destruction, backups unreadable; leakage of data, sharing of data, misuse of resources, ... hmm seems like another matrix. Actor / act / summary effect ?

A(dan) I'm tempted to address these in the RA table below.

Risk Assessment

Systems

Risk IDs are a concatination of the system, the security risk (Confidentiality/ Integrity / Availability) plus a unique identifier.

• id	Asset	Threat	Likelihood	Consequence	Resultant Risk	Treatment	Likelihood (after treatment)	Consequence (after treatment)	Risk (after treatment
  RK.C.1	Confidentiality of Root key	Criminal Fraud Organisations	Unlikely	Major	High	Physical Access control + tamper zeroisation	Rare	Major	Medium
  RK.C.2	Confidentiality of Root key backup	Criminal Fraud Organisations	Unlikely	Major	High	Bank Vault	Rare	Major	Medium
  RK.I	Root Key integrity	Rival CA/cracker	Moderate	Unlikely	Low	not required
  RK.A	Root key availability (long term)	Risk RK.C.1 or Legal supenona	unlikely	Major	High	accessable backup/restore procedures + multi country operation	Rare	Major	Medium
  SM.I	Signing mechanism tampered	Rival CA/cracker	Unlikely	Major	High	Audit Procedures to detect false signature issue	Rare	Major	Medium
  SM.A	Signing mechanism availability long term	Rival CA/cracker	Unlikely	Major	High	per RK.A	Rare	Major	Medium
  OCSP.I	OCSP/CRL points compromised resulting in - DoS against legitimate users (invalid status for valid cert)/ (valid status for invalid certificate)	Criminal Fraud organisation / Cracker / Rival CA	Unlikely	Major	High	trusted services
  OCSP.A	DDoS of CRL/OCSP	Extortion from Criminal Fraud Organisation/ Cracker/Rival CA	Unlikely	Major	High	Service redundacy (possible?)	Rare	Major	Medium
  DNS.I	False DNS entries for main website/ crl/OCSP	Cracker/Rival CA/Criminal Fraud	Unlikely	Major	High	Change Control + Integrity monitoring services with action to fix/shutdown. Low TTL policy(?). DNSSEC	Unlikely	Moderate	Medium
  DNS.A	DNS unavailable due to DDoS	As per OCSP.A	Rare	Major	Medium	Addition services if DNS.I treatments can occur	Rare	Moderate	Medium
  UDB.C	User database compromised	Crackers/Rival CA, Criminal Fraudsters	Possible	Major	Extreme	Triggers for unexpected queries to shutdown DB + CodeAudit on main interface + IDS on SM	Unlikely	Moderate	Low
  UDB.I	User database corrupted	Criminal Fraudsters through assurer extortion to obtain lucretive certificates	Possible	Moderate	Medium	Spot checking on domains/assurances	Possible	Minor	Low

Mozilla Criteria

These are based of the Mozilla CA Certificate Policy (1.2). The numbers reflect the requirement in http://www.mozilla.org/projects/security/certs/policy/.

• id	Asset	Threat	Likelihood	Consequence	Resultant Risk	Treatment	Likelihood (after treatment)	Consequence (after treatment)	Risk (after treatment
  MOZ.4.U	Issuing certificates without the knowledge of the entities whose information is referenced in the certificates	Internal errors/malicious insiders
  MOZ.4.F	knowingly issue certificates that appear to be intended for fraudulent use.	Internal errors/malicious insiders
  MOZ.4.T.1	ASN.1 DER encoding errors, invalid public keys, duplicate issuer names and serial numbers, incorrect extensions	Internal errors/malicious insiders
  MOZ.4.T.2	cRLDistributionPoints or OCSP authorityInfoAccess extensions for which no operational CRL or OCSP service exists.	Internal errors/malicious insiders
  MOZ.6.I	provide some service relevant to typical users of our software products	Internal errors/malicious insiders
  MOZ.6.F	publicly disclose information about their policies and business practices	Internal errors/malicious insiders
  MOZ.6.V	prior to issuing certificates, verify certificate signing requests in a manner acceptable to Mozilla Foundation	Internal errors/malicious insiders
  MOZ.6.G	provide attestation of their conformance to the stated verification requirements and other operational criteria by a competent independent party or parties with access to details of the CA's internal operations	Poor governance
  MOZ.7.CV	for a certificate to be used for digitally signing and/or encrypting email messages, the CA takes reasonable measures to verify that the entity submitting the request controls the email account associated with the email address referenced in the certificate or has been authorized by the email account holder to act on the account holder's behalf	Internal errors/malicious insiders
  MOZ.7.SV	for a certificate to be used for SSL-enabled servers, the CA takes reasonable measures to verify that the entity submitting the certificate signing request has registered the domain(s) referenced in the certificate or has been authorized by the domain registrant to act on the registrant's behalf;	Internal errors/malicious insiders
  MOZ.7.CS	for certificates to be used for digitally signing code objects, the CA takes reasonable measures to verify that the entity submitting the certificate signing request is the same entity referenced in the certificate or has been authorized by the entity referenced in the certificate to act on that entity's behalf;	Internal errors/malicious insiders
  MOZ.7.EV	Complies with Guidelines for the Issuance and Management of Extended Validation Certificates and erratum	Internal errors/malicious insiders

Legal

• id	Asset	Threat	Likelihood	Consequence	Resultant Risk	Treatment	Likelihood (after treatment)	Consequence (after treatment)	Risk (after treatment

References

• Risk Management Guide for Information Technology Systems

• RisksLiabilitiesObligations

• Audit/CommunityReport20080602

• Board/Minutes/20080229

• Advisory/AMinutes20080416

• OverviewProjectsBoard/AuditToDo

• ThreatList

• Security Policy and SecurityManual

  • Older SM and threat analysis by Philipp Güring

Footnotes

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• CategoryAudit