Implementing Vulnerability SLA Breach Alerting

Overview

Vulnerability remediation SLAs define maximum timeframes for addressing security findings based on severity. This skill covers building an automated alerting system that tracks remediation timelines, detects SLA breaches, sends escalation notifications, and generates compliance reports. Industry-standard SLA targets are: Critical (24-48 hours), High (15-30 days), Medium (60 days), Low (90 days).

When to Use

• When deploying or configuring implementing vulnerability sla breach alerting capabilities in your environment
• When establishing security controls aligned to compliance requirements
• When building or improving security architecture for this domain
• When conducting security assessments that require this implementation

Prerequisites

• Python 3.9+ with requests, pandas, jinja2, smtplib libraries
• Vulnerability management platform with API access (DefectDojo, Qualys, Tenable)
• SMTP server or webhook endpoint (Slack, Microsoft Teams, PagerDuty)
• Database for SLA tracking (PostgreSQL or SQLite)

SLA Policy Definition

Standard SLA Tiers

SLA Configuration File

# sla_policy.yaml
sla_tiers:
  critical:
    cvss_min: 9.0
    cvss_max: 10.0
    remediation_days: 2
    grace_period_days: 0.5
    escalation_contacts:
      - [email protected]
      - [email protected]
    pagerduty_severity: critical
  high:
    cvss_min: 7.0
    cvss_max: 8.9
    remediation_days: 15
    grace_period_days: 5
    escalation_contacts:
      - [email protected]
    pagerduty_severity: high
  medium:
    cvss_min: 4.0
    cvss_max: 6.9
    remediation_days: 60
    grace_period_days: 14
    escalation_contacts:
      - [email protected]
    pagerduty_severity: warning
  low:
    cvss_min: 0.1
    cvss_max: 3.9
    remediation_days: 90
    grace_period_days: 30
    escalation_contacts:
      - [email protected]
    pagerduty_severity: info

notification_channels:
  slack:
    webhook_url: "${SLACK_WEBHOOK_URL}"
    channel: "#vulnerability-alerts"
  email:
    smtp_host: smtp.company.com
    smtp_port: 587
    from_address: [email protected]
  pagerduty:
    api_key: "${PAGERDUTY_API_KEY}"
    service_id: "${PAGERDUTY_SERVICE_ID}"

alert_schedules:
  approaching_breach:
    percentage_elapsed: 80
    frequency_hours: 24
  at_breach:
    notification: immediate
    escalation: true
  post_breach:
    frequency_hours: 12
    escalation_increase: true

Workflow

Step 1: Database Schema for SLA Tracking

CREATE TABLE vulnerability_sla (
    id SERIAL PRIMARY KEY,
    cve_id VARCHAR(20) NOT NULL,
    finding_id VARCHAR(100) NOT NULL,
    asset_hostname VARCHAR(255),
    severity VARCHAR(20) NOT NULL,
    cvss_score DECIMAL(3,1),
    discovered_at TIMESTAMP NOT NULL,
    sla_deadline TIMESTAMP NOT NULL,
    remediated_at TIMESTAMP,
    status VARCHAR(20) DEFAULT 'open',
    owner_email VARCHAR(255),
    escalation_level INTEGER DEFAULT 0,
    last_alert_sent TIMESTAMP,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX idx_sla_status ON vulnerability_sla(status);
CREATE INDEX idx_sla_deadline ON vulnerability_sla(sla_deadline);
CREATE INDEX idx_sla_severity ON vulnerability_sla(severity);

Step 2: SLA Breach Detection Logic

from datetime import datetime, timedelta, timezone
import yaml

def load_sla_policy(policy_path="sla_policy.yaml"):
    with open(policy_path, "r") as f:
        return yaml.safe_load(f)

def get_sla_tier(cvss_score, policy):
    for tier_name, tier in policy["sla_tiers"].items():
        if tier["cvss_min"] <= cvss_score <= tier["cvss_max"]:
            return tier_name, tier
    return "low", policy["sla_tiers"]["low"]

def calculate_sla_deadline(discovered_at, cvss_score, policy):
    tier_name, tier = get_sla_tier(cvss_score, policy)
    deadline = discovered_at + timedelta(days=tier["remediation_days"])
    return deadline, tier_name

def check_sla_status(discovered_at, sla_deadline, remediated_at=None):
    now = datetime.now(timezone.utc)
    if remediated_at:
        if remediated_at <= sla_deadline:
            return "remediated_within_sla"
        return "remediated_breach"
    if now > sla_deadline:
        overdue_days = (now - sla_deadline).days
        return f"breached_{overdue_days}d_overdue"
    remaining = sla_deadline - now
    total_sla = sla_deadline - discovered_at
    pct_elapsed = ((total_sla - remaining) / total_sla) * 100
    if pct_elapsed >= 80:
        return "approaching_breach"
    return "within_sla"

Step 3: Notification Dispatch

import requests
import json
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

def send_slack_alert(webhook_url, vuln_data, sla_status):
    color = {"breached": "#FF0000", "approaching_breach": "#FFA500", "within_sla": "#36A64F"}
    status_color = color.get("breached" if "breached" in sla_status else sla_status, "#808080")
    payload = {
        "attachments": [{
            "color": status_color,
            "title": f"Vulnerability SLA Alert: {vuln_data['cve_id']}",
            "fields": [
                {"title": "Severity", "value": vuln_data["severity"], "short": True},
                {"title": "CVSS", "value": str(vuln_data["cvss_score"]), "short": True},
                {"title": "Asset", "value": vuln_data["asset_hostname"], "short": True},
                {"title": "SLA Status", "value": sla_status, "short": True},
                {"title": "Deadline", "value": vuln_data["sla_deadline"].strftime("%Y-%m-%d %H:%M UTC"), "short": True},
                {"title": "Owner", "value": vuln_data.get("owner_email", "Unassigned"), "short": True},
            ],
        }]
    }
    requests.post(webhook_url, json=payload, timeout=10)

def send_pagerduty_alert(api_key, service_id, vuln_data, severity):
    payload = {
        "routing_key": api_key,
        "event_action": "trigger",
        "payload": {
            "summary": f"SLA Breach: {vuln_data['cve_id']} on {vuln_data['asset_hostname']}",
            "severity": severity,
            "source": vuln_data["asset_hostname"],
            "custom_details": {
                "cve_id": vuln_data["cve_id"],
                "cvss_score": vuln_data["cvss_score"],
                "sla_deadline": vuln_data["sla_deadline"].isoformat(),
            }
        }
    }
    requests.post(
        "https://events.pagerduty.com/v2/enqueue",
        json=payload, timeout=10
    )

def send_email_alert(smtp_config, to_addresses, vuln_data, sla_status):
    msg = MIMEMultipart("alternative")
    msg["Subject"] = f"[SLA {sla_status.upper()}] {vuln_data['cve_id']} - {vuln_data['severity']}"
    msg["From"] = smtp_config["from_address"]
    msg["To"] = ", ".join(to_addresses)
    body = f"""
    Vulnerability SLA Alert

    CVE: {vuln_data['cve_id']}
    Severity: {vuln_data['severity']} (CVSS {vuln_data['cvss_score']})
    Asset: {vuln_data['asset_hostname']}
    SLA Deadline: {vuln_data['sla_deadline'].strftime('%Y-%m-%d %H:%M UTC')}
    Status: {sla_status}
    Owner: {vuln_data.get('owner_email', 'Unassigned')}

    Please take immediate action to remediate this vulnerability.
    """
    msg.attach(MIMEText(body, "plain"))
    with smtplib.SMTP(smtp_config["smtp_host"], smtp_config["smtp_port"]) as server:
        server.starttls()
        server.send_message(msg)

Step 4: Scheduled SLA Check Runner

# Run SLA breach check every hour via cron
echo "0 * * * * cd /opt/vuln-sla && python3 scripts/process.py --check-sla" | crontab -

# Manual check
python3 scripts/process.py --check-sla --policy sla_policy.yaml

# Generate SLA compliance report
python3 scripts/process.py --report --period monthly --output sla_report.html

SLA Metrics Dashboard

Key Performance Indicators

def calculate_sla_metrics(db_connection, period_start, period_end):
    metrics = {
        "total_findings": 0,
        "remediated_within_sla": 0,
        "sla_breach_count": 0,
        "mean_time_to_remediate": {},
        "sla_compliance_rate": 0.0,
        "current_overdue": 0,
    }
    # Query findings in period grouped by severity
    query = """
        SELECT severity, COUNT(*) as total,
               SUM(CASE WHEN remediated_at <= sla_deadline THEN 1 ELSE 0 END) as within_sla,
               AVG(EXTRACT(EPOCH FROM (COALESCE(remediated_at, NOW()) - discovered_at))/86400) as avg_days
        FROM vulnerability_sla
        WHERE discovered_at BETWEEN %s AND %s
        GROUP BY severity
    """
    return metrics

References

• Vulnerability Management SLAs Guide
• NIST SP 800-40 Rev 4 - Patch Management
• PagerDuty Events API v2
• Slack Incoming Webhooks