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description: Security Review - Bandit Findings: Date: 2026-01-26 Reviewer: Automated code quality review Tool: Bandit v1.8.6 --- ## Summary **2 medium-severity f

Security Review - Bandit Findings

Date: 2026-01-26 Reviewer: Automated code quality review Tool: Bandit v1.8.6

Summary

2 medium-severity findings identified - BOTH ARE FALSE POSITIVES

The Bandit static analysis tool flagged 2 security issues, but upon manual review, both are false positives. The code implements proper security controls.

Finding 1: B104 - Hardcoded Bind to All Interfaces

Status: ✅ FALSE POSITIVE Severity: Medium Confidence: Medium Location: src/attune/monitoring/alerts.py:88

Bandit Report

Issue: [B104:hardcoded_bind_all_interfaces] Possible binding to all interfaces.
CWE: CWE-605 (https://cwe.mitre.org/data/definitions/605.html)

Code Context

# Line 85-94
blocked_hosts = {
    "localhost",
    "127.0.0.1",
    "0.0.0.0",  # ← Flagged by Bandit
    "::1",
    "[::1]",
    "169.254.169.254",  # AWS metadata
    "metadata.google.internal",  # GCP metadata
    "instance-data",  # Azure metadata pattern
}

Analysis

This is a blocklist, not a bind address.

The code defines a set of prohibited webhook destinations to prevent SSRF (Server-Side Request Forgery) attacks. The string "0.0.0.0" appears in a list of addresses that are explicitly blocked, not as a server bind configuration.

Security impact: POSITIVE - This code prevents SSRF by blocking requests to 0.0.0.0.

Recommendation

✅ No action required

To suppress this false positive in future scans, add a Bandit comment: 

blocked_hosts = {
    "localhost",
    "127.0.0.1",
    "0.0.0.0",  # nosec B104 - blocklist for SSRF prevention, not bind address
    "::1",
    ...
}

Finding 2: B310 - URL Open Without Scheme Validation

Status: ✅ FALSE POSITIVE (with proper validation) Severity: Medium Confidence: High Location: src/attune/monitoring/alerts.py:777

Bandit Report

Issue: [B310:blacklist] Audit url open for permitted schemes.
       Allowing use of file:/ or custom schemes is often unexpected.
CWE: CWE-22 (https://cwe.mitre.org/data/definitions/22.html)

Code Context

# Line 726
validated_url = _validate_webhook_url(alert.webhook_url)

# Line 770-777
req = urllib.request.Request(
    validated_url,
    data=data,
    headers={"Content-Type": "application/json"},
)

try:
    with urllib.request.urlopen(req, timeout=10) as response:  # ← Flagged by Bandit
        ...

Analysis

The URL is validated before use through _validate_webhook_url().

The validation function (lines 56-120) implements comprehensive security checks:

  1. Scheme validation (line 74-77): 

    if parsed.scheme not in ("http", "https"):
    raise ValueError(
        f"Invalid scheme '{parsed.scheme}'. Only http and https allowed for webhooks."
    )

  2. Hostname validation (line 80-82): 

    hostname = parsed.hostname
if not hostname:
    raise ValueError("Webhook URL must contain a valid hostname")

  3. SSRF prevention (line 85-98):

  4. Blocks localhost addresses (127.0.0.1, ::1, 0.0.0.0)
  5. Blocks cloud metadata services (AWS, GCP, Azure)

  6. Blocks private IP ranges (10.x, 172.16-31.x, 192.168.x)

  7. Port restrictions (line 106-115):

  8. Blocks common internal service ports (Redis 6379, PostgreSQL 5432, etc.)

Security impact: POSITIVE - The code properly prevents: - File scheme access (file://) - SSRF attacks via localhost/private IPs - Access to cloud metadata services - Access to internal service ports

Recommendation

✅ Code is secure - validation is comprehensive

To suppress this warning, add a Bandit comment explaining the validation: 

# nosec B310 - URL validated by _validate_webhook_url() - only http/https allowed, SSRF protected
with urllib.request.urlopen(req, timeout=10) as response:
    ...

Overall Security Posture

Assessment: ✅ EXCELLENT

The alerts.py module demonstrates strong security practices: - Comprehensive input validation - SSRF attack prevention - Allowlist approach (only http/https schemes) - Protection against cloud metadata access - Private IP range blocking - Internal port blocking

No security vulnerabilities identified in this review.

Recommendations for Future

  1. Add # nosec comments to suppress false positives in CI/CD
  2. Document validation functions in security documentation
  3. Add unit tests for SSRF prevention edge cases (if not already present)
  4. Consider adding rate limiting for webhook deliveries
  • Security implementation: src/attune/monitoring/alerts.py
  • Security standards: .claude/rules/attune/coding-standards-index.md
  • Security policy: SECURITY.md

Review Status: COMPLETE Action Required: None (false positives) Next Review: After significant webhook/alert changes