agentleFS
sunilgentyalasunilgentyala/OmniRed/skills/utility/cvss4-scoring/SKILL.md

cvss4-scoring

Skill5 starsChanged 5 months agoApache-2.0View on GitHub

CVSS v4.0 scoring guide for red team findings. Covers all metric groups (Base, Threat, Environmental, Supplemental), AI/LLM-specific scoring considerations, and OWASP LLM Top 10 to CVSS mapping.

The file

We split this skill into the rules it gives an agent

1 rule. About 0 are common, 1 is distinctive, and 0 are very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈1

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 0

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Use the official FIRST calculator: https://www.first.org/cvss/calculator/4-0

    line 114

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

CVSS v4.0 Scoring Guide

Base Metrics

Exploitability Metrics

MetricValuesNotes
AV (Attack Vector)N/A/L/PNetwork=remotely exploitable; Physical=requires device
AC (Attack Complexity)L/HH=requires specific conditions or luck
AT (Attack Requirements)N/PP=target must be in non-default configuration
PR (Privileges Required)N/L/H
UI (User Interaction)N/P/AN=no user needed; A=user must actively engage

Impact Metrics (Vulnerable System)

MetricValues
VC (Confidentiality)H/L/N
VI (Integrity)H/L/N
VA (Availability)H/L/N

Impact Metrics (Subsequent Systems)

MetricValuesNotes
SC (Confidentiality)H/L/NImpact on other systems in scope
SI (Integrity)H/L/N
SA (Availability)H/L/N

Common Findings — Quick Scores

FindingCVSS v4.0 VectorScore
Unauthenticated RCEAV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H10.0
SQLi (auth bypass)AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N9.3
Stored XSS (session hijack)AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N7.1
Reflected XSSAV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N5.3
SSRF (internal)AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N8.6
IDOR (read)AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N7.1

AI/LLM-Specific Scoring

Standard CVSS was designed for traditional software. Apply these adjustments for AI vulnerabilities:

Prompt Injection (Direct)

AV:N — Network (user input over API/web)
AC:L — No special conditions
AT:N — Default configurations are vulnerable
PR:N — Unauthenticated in most products
UI:N — No user interaction beyond sending the prompt
VC:H — System prompt, tool configs, session data
VI:H — Agent can be directed to take harmful actions
VA:N — Usually doesn't affect availability
SC:H — Multi-agent pipelines: subsequent systems affected

Indirect Prompt Injection (via RAG/web)

AV:N — Attacker controls external content
AC:H — Requires agent to retrieve attacker content
AT:P — Requires agent to have retrieval capability
PR:N — No credentials needed (content is public)
UI:N — Agent retrieves autonomously
SC:H — High: affects all users who trigger retrieval

MCP Tool Poisoning

AV:N — Network (unauthenticated tools/list)
AC:L — Low (no special conditions)
AT:N — None
PR:N — Unauthenticated endpoint
UI:N — Agent connects automatically
VC:H — Full context window visible to poisoned tool
VI:H — Agent can be directed to write files, call APIs
SC:H — Other MCP servers and downstream agents affected
Score: ~9.3

Threat Metrics (Optional)

E (Exploit Maturity)
  - U = Unreported
  - P = Proof-of-Concept
  - A = Attacked (in-the-wild exploitation confirmed)

Supplemental Metrics

S (Safety)         — N/P: physical harm possible
AU (Automatable)   — N/Y: can be automated at scale
R (Recovery)       — A/U/I: automatic/user/irrecoverable
V (Value Density)  — D/C: diffuse/concentrated
RE (Effort)        — L/M/H: low/medium/high response effort
U (Urgency)        — Clear/Green/Amber/Red

Calculator

Use the official FIRST calculator: https://www.first.org/cvss/calculator/4-0

Download now (ZIP)

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