SC-4 Information in shared system resources
Requires the system to prevent unauthorized and unintended transfer of information through shared resources such as memory, storage and caches, so that residual data from one user or process is not exposed to another.
4
artefacts
1
held by a system
1
at each review
moderate
to go live
Source control / CI pipeline
where the evidence lives
teal = a system already holds it · olive = produced at each review
system holds itEvidence a system already holds
- Configuration evidence for memory and storage sanitisation on release · Source control / CI pipeline
periodic reviewEvidence produced at each review
- Test results showing no residual data is readable by a subsequent process · Source control / CI pipeline
governing documentDocuments that govern the control
- Design documentation of how shared resources are cleared or partitioned between users · Document repository
- Treatment of shared caches and temporary storage in multi tenant components · Document repository
First move
Start with the 1 of 4 artefacts that already live in a system (Source control / CI pipeline); keep the periodic reviews but log each one as a dated record with a named reviewer.
Common gaps auditors find
- Temporary files and caches persist between users on shared systems
- Object storage reused without clearing, exposing previous content
- Shared caches keyed in a way that lets one tenant read another tenant's response
Do this for your whole sheet
Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.
Build my evidence sheetSC-3 Security Function Isolation. Isolate security functions from nonsecurity functions · SC-5 Denial-of-service protection