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Cybersecurity

Cybersecurity

Cybersecurity protects services, identities and data against compromise, alteration and disruption. This topic connects vulnerability management, authentication, detection and incident response. Start with exposed assets and critical activities, then connect each priority to verifiable evidence and an accountable owner.

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How do you distinguish an alert, a score and evidence of compromise? An alert starts an investigation; a score supports ranking; evidence connects an observation to an asset, a period and an activity. Keep those records separate so a theoretical vulnerability is not treated as a confirmed incident. Priority also depends on accessible data and the affected service.

For a management review, show exposed access paths, temporary controls and closure checks. Counting installed patches is insufficient: identify the services actually verified, exceptions still open and the person deciding on residual risk. The NIST and FIRST references alongside this text help clarify methods and terminology.

In this topic

Vulnerabilities · Ransomware · Identity · Incident response · Cloud security

Practical guides

Build a practical cybersecurity baseline

How do you build a useful cyber defence? Connect protected assets, access paths, detection signals and actual restoration capability. This guide provides six checks to turn an inventory into an action plan. The expected output is a dated register covering the asset, exposure, business consequence, control, evidence, owner and next check. Examples describe working protocols, not completed audit results.

Read the guide

Intelligence watch

Open the news desk →

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References: data, uses and limitations

Documentation reviewed on .

Vulnerability: three complementary viewsCVE · Identify. CVSS · Technical severity. EPSS · Probability. KEV · Known exploitation. Affected version and product. Score from 0.0 to 10.0. 30-day horizon. Official CISA catalogue. Local decision: exposure, impact, evidence and remediation checks.Vulnerability: three complementary viewsCVE · IdentifyAffected version and productCVSS · Technical severityScore from 0.0 to 10.0EPSS · Probability30-day horizonKEV · Known exploitationOfficial CISA catalogueLocal decision: exposure, impact, evidence and remediation checks
Vulnerability: three complementary views
References: data, uses and limitations
Source and purposeVerified data or benchmarkHow to use itLimitation to retain
FIRST · CVSS

Describe technical vulnerability severity using an explicit method and vector.

CVSS 4.0 scores run from 0.0 to 10.0. Base, Threat, Environmental and Supplemental metric groups serve different purposes. Retain the score version, vector and date. Compare it with the installed version, access paths and business consequences before ordering remediation.

Explore the method →

A high score is not evidence of exploitation; a low score does not mean a service has no risk.
FIRST · EPSS

Estimate exploitation probability for a published CVE.

The model looks ahead 30 days. Its score is a probability; its percentile ranks that score relative to other CVEs. Record the data date and distinguish probability from percentile. Add asset exposure and confirmed exploitation evidence.

Explore the method →

The model does not predict harm to your organisation. Low probability does not cancel a critical exposure.
CISA · Known Exploited Vulnerabilities

Identify vulnerabilities listed by CISA as known to be exploited.

The catalogue includes CVE, product, date added and required action. Its official repository also provides the data schema. Check applicability to your products and retain the access date. Review the requested action and vendor advisory before confirming remediation.

Explore the method →

Absence from the catalogue does not establish safety. Administrative deadlines in it are not automatically binding on every organisation.
CVE Program

Link discussions to the same vulnerability record.

A JSON schema defines the CVE record format. An identifier and the published contents of its record are distinct things. Open the record and references; check its state, described affected versions and supplier information. Keep the identifier in action tracking.

Explore the method →

A CVE identifier is neither a severity score nor proof that your installation is affected.

Identity: factors, sessions and recovery

Identity protection continues after sign-in

A phishing-resistant factor alone does not address new-authenticator binding, recovery or existing sessions. Describe these paths for accounts controlling critical services.

  • Separate user presence (UP) and user verification (UV) evidence.
  • Document syncable methods and their recovery account.
  • Test loss, revocation and existing sessions with observable outcomes.

Open the authenticator and recovery comparison →

Sources consulted on · NIST SP 800-63B-4 · final publication NIST · Authenticator Event Management W3C · WebAuthn Level 3

Cyber incidents: recovery decisions and evidence

Prepare the decisions connecting response and recovery

Response capability is tested through the connection between signal, authority, evidence and usable service.

  • Link provisional triage to facts and a planned reassessment.
  • Exercise recovery initiation and the two integrity checks, before and after restoration.
  • Retain closure criteria, decision maker and residual actions.

Explore NIST outcomes and the timeline →

References reviewed · NIST SP 800-61r3 · pp. 27–29, 34–35 · CSF 2.0 · Appendix A

security.txt and disclosure

Check that an external report reaches a team

Cyber exposure also includes the ability to receive a useful report. A security.txt file can make the contact discoverable, but its presence alone establishes neither channel availability nor case follow-through.

  • Check /.well-known/security.txt, HTTPS, Contact fields and exactly one Expires.
  • Preserve the exact host, redirects and policy link; do not extend scope to subdomains by default.
  • Assign a publication owner and a report handler; distinguish receipt, assessment and remediation.

Read the security.txt reference and disclosure cases →

Sources checked on · IETF · RFC 9116 · §2.5, §3, §5

CVSS, EPSS, KEV and VEX

Preserve the facts justifying remediation order

An exposure review is more useful when each vulnerability connects to an instance and decision. Keep generic scores identifiable and dated, then relate them to the exposed service.

  • Separate CVSS severity, EPSS probability, KEV listing and VEX applicability assertions.
  • Establish product, version, access paths and owner before declaring local exposure.
  • Record decision, interim control and verification evidence; an available patch is not a deployed fix.

Read the CVSS, EPSS, KEV and VEX reference →

Sources checked on · FIRST · CVSS 4.0 Specification · FIRST · EPSS Frequently Asked Questions · CISA · KEV official data schema · OpenVEX · Specification v0.2.0

Timelines: UTC and time zones

Reconcile logs without inventing their order

A later-received record can describe earlier activity. Clock changes and collection retries add ambiguity; sorting local strings does not produce a reliable incident timeline.

  • Reconcile UTC instants while retaining received representations.
  • Test repeated time, missing time and inconsistent offsets.
  • Isolate conflicting identifiers and preserve every dated analysis snapshot.

Read the 12 cases and three dated snapshots →

Sources reviewed on · IETF · RFC 3339 · Python · PEP 495 · Python 3.12 · zoneinfo · IANA · Time Zone Database 2026e · IANA · 2026e Europe rules · OpenTelemetry · Logs Data Model

Files: quarantine and withdrawal

Include late tasks in file acceptance tests

Acceptance tests should trigger withdrawal or replacement while analysis is running. Expected behavior concerns final state and actual access, beyond the task’s own success status.

  • Test failure, incomplete checks and retry.
  • Change version or policy during a task and verify rejection.
  • Withdraw access before a derivative returns, then replay permitted and forbidden reads.

View the three journeys and late task results →

Sources reviewed on · OWASP · File Upload Cheat Sheet · OWASP · Authorization Cheat Sheet · WHATWG · HTML input accept · PostgreSQL 18 · Transaction isolation