Immunity
- Immunity
- the
software integrity
quality subfactor
representing the degree to which the malicious corruption
of software by infection (i.e., malicious
corruption) by malware (e.g., viruses, worms, Trojan horses,
and adware) is properly handled
The typical objectives of immunity are to:
- Ensure that security in general (and immunity in particular)
properly addresses the harm that can be caused by malicious infection
(i.e., malicious corruption) by malware (e.g., viruses, worms, Trojan horses,
and adware) of valuable software
- Model the degree to which malicious infection of software is:
- Prevented
- Detected
- Reacted to
- Adapted to
- Support the analysis and specification of
integrity requirements
Immunity is typically measured in terms of:
- [Number/percentage] of [software components of a given
type] that are corrupted [in a given way] [to a given degree]
[per unit of time] [when under attack [of a given type] [of a
given level of sophistication]]
- [Number/percentage] of attacks [of a given type] [of a
given level of sophistication] that [succeed/fail] [per unit
of time]
- [Number/percentage] of malicious programs
[identified/prevented from causing infection/cured (e.g.,
removed from infected machine)]
Typical mechanisms for implementing support for immunity
include:
- Commercial-off-the-shelf (COTS) antivirus programs
(including scanning, disinfection, repair, and updating of
virus definitions)
- Firewalls
- Prohibition of type-unsafe languages (e.g., C) that may
allow buffer overflows that contain malicious scripts
- Programming standards (e.g., for ensuring type safety and
array bounds checking)
- Prohibition of less safe operating systems
The following guidelines have been found to be useful with
regard to immunity:
- Personnel integrity deals with the following security concepts:
| Security Concept |
Value |
| Valuable Asset |
Software |
| Malicious Harm |
Unauthorized infection of software |
| Security Incident(s) |
Software infecting attacks (e.g., virus, work, Trojan horse, logic bomb) |
| Threat |
Existence of attacker(s) with means and motive to infect software |
| Security Risk |
Can be low or high depending on the number and types of malicious software programs,
the number of motivated attackers and their profiles,
the appropriate security countermeasures, and
and vulnerabilities that can be exploited by attack |