ROSI Calculator 1.2
-
Upload
robert-alan -
Category
Documents
-
view
8 -
download
3
Transcript of ROSI Calculator 1.2
NSW Dept of Commerce OICT ROSI TOOL V1.0
Sample Threat & Risk Assessment PLUS Cost Analysis
Legend Purple cells contain values to be entered by the user
Yellow cells contain calculated results
Grey cells are copied as is from an actual TRA
TABLE 1 LIKELIHOOD GRADE TRANSORMED TO FREQUENCY Max freq p.a.
Negligible 0.05
Very Low 0.5
Low 1.0
Medium 2.0
High 12.0
Very High 50.0
Extreme 500.0
TABLE 2 SEVERITY GRADE TRANSFORMED TO DIRECT COST Cost
Insignificant -$
Minor
1,000$
Significant
10,000$
Damaging
100,000$
Serious
1,000,000$
Grave
10,000,000$
RISK CALCULATIONS
Will have some minor effect on the asset value. Will not require any extra effort to repair or
reconfigure the system.
Unlikely to occur
Likely to occur two/three times every five years
Likely to occur once every year or less
Likely to occur once every six months or less
Likely to occur multiple times per day
Likely to occur multiple times per month or less
Will have almost no impact if threat is realised.
Likely to occur once per month or less
May cause system to be permanently closed, and/or be subsumed by another (secure)
environment. May result in complete compromise of Government agencies.
Will result in some tangible harm, albeit only small and perhaps only noted by a few
individuals or agencies. Will require some expenditure of resources to repair (eg "political
embarrassment").
May cause damage to the reputation of system management, and/or notable loss of
confidence in the system's resources or services. Will require expenditure of significant
resources to repair.
May cause extended system outage, and/or loss of connected customers or business
confidence. May result in compromise of large amounts of Government information or
services.
Insignificant Minor Significant Damaging Serious Grave
Negligible Negligible Negligible Negligible Negligible Negligible Negligible
Very Low Negligible Low Low Low Medium Medium
Low Negligible Low Medium Medium High High
Medium Negligible Low Medium High High Critical
High Negligible Medium High High Extreme Extreme
Very High Negligible Medium High Critical Extreme Extreme
Extreme Negligible Medium High Critical Extreme Extreme
ANNUAL INCIDENT COST AT EACH RISK POINT
Capped at cost of a single Grave incident
Insignificant Minor Significant Damaging Serious Grave
Annual Prob $ - $ 1,000 $ 10,000 $ 100,000 $ 1,000,000 10,000,000$
Negligible 0.05 $ - $ 50 $ 500 $ 5,000 $ 50,000 $ 500,000
Very Low 0.50 $ - $ 500 $ 5,000 $ 50,000 $ 500,000 $ 5,000,000
Low 1.00 $ - $ 1,000 $ 10,000 $ 100,000 $ 1,000,000 $ 10,000,000
Medium 2.00 $ - $ 2,000 $ 20,000 $ 200,000 $ 2,000,000 $ 10,000,000
High 12.00 $ - $ 12,000 $ 120,000 $ 1,200,000 $ 10,000,000 $ 10,000,000
Very High 50.00 $ - $ 50,000 $ 500,000 $ 5,000,000 $ 10,000,000 $ 10,000,000
Extreme 500.00 $ - $ 500,000 $ 5,000,000 $ 10,000,000 $ 10,000,000 $ 10,000,000
Lik
elih
oo
d
Degree of Harm and Cost per Incident
Degree of Harm
Lik
elih
oo
d
Department of Fiance and Services ROSI TOOL V1.0
Sample Threat & Risk Assessment PLUS Cost Analysis
Legend Purple cells contain values to be entered by the user
Yellow cells contain calculated results
Grey cells are copied as is from an actual TRA
Sample Threat & Risk Assessment PLUS Cost Analysis
No. Asset Potential incident
(Threat to the Asset)
Likelihood Severity Estimated
Risk
Annual rate
of
occurrence
Direct Cost
per incident
Opportunity
Cost per
incident
Total
UNTREATED
Annual Cost
0.05 $ 1,000,000 $ 50,000
2 $ 10,000 $ 20,000
1 $ 1,000,000 $ 1,000,000
0.5 $ 100,000 $ 50,000
1 $ 10,000 $ 10,000
0.5 $ 10,000 $ 5,000
Failure of Cooling System Medium
Significant
Serious Nil
Significant Medium
Misconfiguration of key
infrastructure e.g. routers,
PIX, switches)
Low
A9
Destruction of key
infrastructure e.g. routers,
PIX, switches)
NegligibleA8 Availability of
D-XYZ internet
connection
Serious High
Damaging Low
Medium
A11 Hardware failure of key
infrastructure e.g. routers,
PIX, switches)
Very Low
A10
Significant Low
A12
A13 Denial of service attack
on carrier or provider
network infrastructure
Very Low
Incorrect building
patching
Low
A14 DNS hardware failure Negligible Damaging Nil 0.05 $ 100,000 $ 5,000
12 $ 100,000 $ 1,200,000
A16 Accidental
misconfiguration of mail
servers
Low Damaging Medium 1 $ 100,000 $ 100,000
ANNUAL TOTALS 2,440,000$
SUMMARY
Annual Cost of Incidents - Untreated 2,440,000$
Annual Cost of Incidents - Residual after Countermeasures 116,600$
Annual Gross Savings 2,323,400$
Countermeasure Upfront Cost 370,000$
Countermeasure Recurring Cost 105,000$
Ammortisation period (years) 3
Ammortised Countermeasure upfront cost 123,333$
Countermeasure Annual Cost 228,333$
Annual Nett Savings 2,095,067$
Damaging HighA15 Availability of
D-XYZ internet
Denial of service attack
on email system
High
Counter Measures Upfront Cost
per Counter-
measure
Recurring Cost
per Counter-
measure
Residual
likelihood
Residual
severity
Total
TREATED
Annual Cost
Saving Per
Threat
Notes
Business Continuity Plan (1) $ 50,000 $ 20,000
Spare parts (4) $ 50,000 $ 10,000
Service level agreements (5) $ - $ -
Physical security (access control
procedures and controls for
computer room) (6)
$ 10,000 $ 10,000
Negligible Minor $ 50 $ 49,950
Environmental controls for
computer room (2)
$ 30,000 $ 5,000
Business Continuity Plan (1) Counted Counted
Service level agreements (5) Counted Counted Very low Minor $ 500 $ 19,500
Configuration management system
(8)
$ 70,000 $ 10,000
Change control procedures (15) $ 30,000 $ 5,000 Negligible Serious $ 50,000 $ 950,000
Business Continuity Plan (1) Counted Counted
Spare parts (4) Counted Counted
Service level agreements (5) Counted Counted Very low Minor $ 500 $ 49,500
Standards for cabling including
labelling and coding (9)
$ 10,000 $ -
Physical security (6) Counted Counted Very low Significant $ 5,000 $ 5,000
Large capacity network connection
(10)
$ 10,000 $ 10,000
Redundant Internet connection (7) $ 10,000 $ 10,000 Very low Minor $ 500 $ 4,500
Harm reduced to Minor by
BCP; Likelihood to Very
Low by Environ controls
Likelihood reduced to
Negligible by Config Mgt
Won't affect the likelihood
of an event, but reduces
harm by better recovery
Redundancy means
minor effect on failover
Replication of DNS server (11) $ 10,000 $ - Negligible Minor $ 50 $ 4,950
Network based Intrusion Detection
System (NIDS) (12)
$ 70,000 $ 20,000
Use DSD evaluated products (13) $ 20,000 $ 5,000
Deny all unless explicitly allowed
firewall rules (14)
$ - $ -
Low Significant $ 10,000 $ 1,190,000
Change control procedures (15)
(including peer review)
Counted Counted
Very low Damaging $ 50,000 $ 50,000
370,000$ 105,000$ 116,600$ 2,323,400$
No amelioration of degree
of harm