Application: GitHub Analyzer / DevAnalyzer Version: 2.0 Analysis Date: 2025-11-29 Python Version: 3.9+

This document provides a comprehensive security analysis of the GitHub Analyzer application. The application is a CLI tool that:

• Fetches data from GitHub and Jira REST APIs
• Processes repository, commit, PR, and issue information
• Exports analysis results to CSV files

Overall Security Posture: EXCELLENT ✅

The codebase demonstrates security-aware design with defense-in-depth measures:

• Proper credential handling via environment variables
• Token masking in all logs and error messages
• Whitelist-based input validation
• HTTPS enforcement for all API connections
• Protection against common injection attacks (command, path traversal, CSV formula)
• Secure file permissions on output files

1. Credential & Secret Management
2. Input Validation & Sanitization
3. Network & API Security
4. File Operations Security
5. Error Handling & Information Disclosure
6. Dependency Security
7. Security Controls Summary
8. Security Checklist

Location: src/github_analyzer/config/settings.py

Implementation:

# Token loaded from environment variable only
token = os.environ.get("GITHUB_TOKEN", "").strip()

Security Controls:

Token Masking (src/github_analyzer/core/exceptions.py:124-137):

def mask_token(value: str) -> str:
    """Mask a token value for safe logging."""
    return "[MASKED]"  # Never reveal any part of the token

Defense-in-Depth URL Masking (src/github_analyzer/core/security.py:55-59):

# Pattern to match potential tokens in URLs
_TOKEN_PATTERN = re.compile(
    r"(ghp_[a-zA-Z0-9]+|gho_[a-zA-Z0-9]+|github_pat_[a-zA-Z0-9_]+|"
    r"[a-f0-9]{40}|Bearer\s+[^\s]+)",
    re.IGNORECASE,
)

Security Grade: A+

Location: src/github_analyzer/config/settings.py, src/github_analyzer/api/jira_client.py

Credentials Involved:

• JIRA_URL - Jira instance URL
• JIRA_EMAIL - User email for authentication
• JIRA_API_TOKEN - API token

Security Controls:

Security Grade: A+

Location: src/github_analyzer/config/validation.py:30-36

Validated Patterns:

TOKEN_PATTERNS = [
    r"^ghp_[a-zA-Z0-9]{20,}$",       # Classic PAT
    r"^github_pat_[a-zA-Z0-9_]{20,}$", # Fine-grained PAT
    r"^gho_[a-zA-Z0-9]{20,}$",       # OAuth
    r"^ghs_[a-zA-Z0-9]{20,}$",       # App token
    r"^ghr_[a-zA-Z0-9]{36,}$",       # Refresh token
]

Purpose: Format validation ensures tokens match expected GitHub patterns, preventing:

• Configuration errors (wrong variable set)
• Accidental exposure of unrelated secrets
• Malformed token usage

Security Grade: A

Location: src/github_analyzer/config/validation.py

Multi-Layer Validation:

Layer 1: Dangerous Character Detection (line 46-47):

DANGEROUS_CHARS = set(";|&$`(){}[]<>\\'\"\n\r\t")

Layer 2: Whitelist Pattern (line 42-43):

REPO_COMPONENT_PATTERN = r"^[a-zA-Z0-9.][a-zA-Z0-9._-]{0,99}$"
REPO_FULL_PATTERN = r"^[a-zA-Z0-9.][a-zA-Z0-9._-]{0,99}/[a-zA-Z0-9.][a-zA-Z0-9._-]{0,99}$"

Layer 3: Path Traversal Protection (line 223-228):

if ".." in owner or ".." in name:
    raise ValidationError(
        "Invalid repository: path traversal attempt detected",
        details="Repository names cannot contain '..'",
    )

Security Controls:

Security Grade: A+

Location: src/github_analyzer/config/validation.py:346

JIRA_PROJECT_KEY_PATTERN = r"^[A-Z][A-Z0-9_]*$"

Validation: Only uppercase letters, digits, and underscores starting with a letter.

Security Grade: A

Location: src/github_analyzer/config/validation.py:349-392

Jira URL Validation:

if parsed.scheme != "https":
    return False  # FR-019: HTTPS mandatory

Controls:

• HTTPS Only: HTTP URLs rejected
• Host Validation: Must have valid hostname with at least one dot
• Dangerous Character Check: Applied to full URL

GitHub URL Normalization:

• Validates against github.com or www.github.com
• Extracts owner/repo from path
• Handles .git suffix removal
• Strips trailing slashes

Security Grade: A

Location: src/github_analyzer/config/validation.py:425-481

Implementation: Validates date format and range (1900-2100) to prevent:

• Injection via malformed dates
• Integer overflow attacks
• Timezone manipulation

Security Grade: A

Security Grade: A+

GitHub (src/github_analyzer/api/client.py:86-96):

def _get_headers(self) -> dict[str, str]:
    return {
        "Authorization": f"token {self._config.github_token}",
        "Accept": "application/vnd.github.v3+json",
        "User-Agent": "GitHub-Analyzer/2.0",
    }

Jira (src/github_analyzer/api/jira_client.py:149-164):

def _get_headers(self) -> dict[str, str]:
    credentials = f"{self.config.jira_email}:{self.config.jira_api_token}"
    encoded = base64.b64encode(credentials.encode()).decode()
    return {
        "Authorization": f"Basic {encoded}",
        ...
    }

Security Controls:

• Credentials only in Authorization header
• Not logged or exposed in errors
• Standard authentication schemes

Security Grade: A

Implementation:

• Tracks X-RateLimit-Remaining and X-RateLimit-Reset
• Raises dedicated RateLimitError / JiraRateLimitError
• Displays wait time without exposing internal details

Security Grade: A

GitHub (src/github_analyzer/api/client.py):

# Only retry on 5xx errors
if e.status_code and 500 <= e.status_code < 600:
    wait_time = (2**attempt) * 0.5  # 0.5s, 1s, 2s
    time.sleep(wait_time)

Jira (src/github_analyzer/api/jira_client.py):

• Max retries: 5
• Initial delay: 1s
• Max delay: 60s
• Respects Retry-After header

Security Benefit: Protects against transient failures without overwhelming servers (prevents unintentional DoS).

Security Grade: A

Both clients implement configurable timeouts (default 30s, max 300s):

timeout=self._config.timeout  # Used in all requests

Timeout Warning (src/github_analyzer/core/security.py:337-373):

def validate_timeout(timeout: int, logger=None, threshold=None):
    """Warn if timeout exceeds recommended threshold (default 60s)."""
    if timeout > threshold and logger:
        logger.warning(f"[SECURITY] Timeout of {timeout}s exceeds recommended threshold")

Security Grade: A

Location: src/github_analyzer/core/security.py:233-285

def validate_content_type(headers, expected="application/json", logger=None):
    """Validate response Content-Type header."""
    if expected not in content_type:
        logger.warning(f"[SECURITY] Unexpected Content-Type: {content_type}")
        return False
    return True

Security Benefit: Detects content-type mismatch attacks and API response tampering.

Security Grade: A

Location: src/github_analyzer/core/security.py:62-99

def validate_output_path(path: str | Path, base_dir: Path | None = None) -> Path:
    """Validate output path is within safe boundary."""
    resolved_base = base_dir.resolve()
    resolved_path = (resolved_base / Path(path)).resolve()

    # Check if path is within safe boundary (Python 3.9+)
    if not resolved_path.is_relative_to(resolved_base):
        raise ValidationError(f"Output path must be within {resolved_base}")

    return resolved_path

Security Controls:

Security Grade: A

Location: src/github_analyzer/core/security.py:102-154

# Formula injection triggers (=, +, -, @, TAB, CR)
FORMULA_TRIGGERS: frozenset[str] = frozenset("=+-@\t\r")

def escape_csv_formula(value: Any) -> str:
    """Escape cell value to prevent CSV formula injection."""
    str_value = str(value) if value is not None else ""
    if str_value and str_value[0] in FORMULA_TRIGGERS:
        return f"'{str_value}"  # Prefix with single quote
    return str_value

Example:

>>> escape_csv_formula("=SUM(A1:A10)")
"'=SUM(A1:A10)"
>>> escape_csv_formula("Normal text")
"Normal text"

OWASP Reference: CSV Injection

Security Grade: A

Location: src/github_analyzer/core/security.py:207-230

# Default secure file permissions (owner read/write only)
DEFAULT_SECURE_MODE: int = 0o600

def set_secure_permissions(filepath: Path, mode: int = DEFAULT_SECURE_MODE) -> bool:
    """Set secure permissions on a file (Unix only)."""
    if platform.system() == "Windows":
        return True  # Different ACL model
    try:
        filepath.chmod(mode)
        return True
    except OSError:
        return False  # Graceful degradation

Security Grade: A

Location: src/github_analyzer/core/security.py:157-204

def check_file_permissions(filepath: Path, logger=None) -> bool:
    """Check if file has secure permissions (Unix only)."""
    is_world_readable = bool(mode & stat.S_IROTH)
    is_group_readable = bool(mode & stat.S_IRGRP)

    if is_world_readable or is_group_readable:
        logger.warning(f"[SECURITY] File '{filepath}' has permissive permissions")
        return False
    return True

Security Grade: A

Location: src/github_analyzer/core/exceptions.py

GitHubAnalyzerError (base)
├── ConfigurationError (exit code 1)
├── ValidationError (exit code 1)
└── APIError (exit code 2)
    └── RateLimitError (exit code 2)

JiraAPIError
├── JiraAuthenticationError (401)
├── JiraPermissionError (403)
├── JiraNotFoundError (404)
└── JiraRateLimitError (429)

Security Benefit: Well-structured hierarchy allows catching specific errors without exposing internal details.

Security Grade: A

Security Controls:

Example (client.py):

raise APIError(
    f"GitHub API error: HTTP {response.status_code}",
    details=response.text[:200] if response.text else None,  # Truncated!
    status_code=response.status_code,
)

Security Grade: A

Location: src/github_analyzer/core/security.py:303-334

def log_api_request(method, url, status_code, logger, response_time_ms=None):
    """Log API request details (for verbose mode)."""
    # Mask any tokens that might appear in the URL (defense-in-depth)
    safe_url = _mask_url_tokens(url)
    logger.info(f"[API] {method} {safe_url} -> {status_code}")

Security Controls:

• No secrets in logs
• URLs sanitized before logging
• Operation-only data logged
• Standard Python logging module

Security Grade: A

Required:

• Python 3.9+ (standard library only)

Optional:

• requests - HTTP client (falls back to urllib if not available)

Security Analysis:

Security Grade: A

Listed in requirements-dev.txt:

• pytest
• pytest-cov
• ruff
• mypy

Note: These are development-only and not required for production use.

• Credentials loaded from environment variables
• Tokens never logged or exposed in errors
• Token format validation before use
• Secure token masking in all representations
• Basic Auth only over HTTPS

• Whitelist validation patterns
• Dangerous character rejection
• Path traversal prevention
• URL scheme validation (HTTPS enforced)
• Maximum length enforcement

• HTTPS enforced for all API calls
• Timeout configuration with warnings
• Rate limit handling
• Retry with exponential backoff
• Content-Type validation
• Proper error handling for network failures

• CSV formula injection protection
• Path validation for output files
• Secure file permissions (0o600)
• Symlink resolution before writes

• No sensitive data in logs
• Error messages sanitized
• CSV properly escaped via csv module
• UTF-8 encoding enforced

• Type hints throughout
• Structured exception handling
• Resource cleanup with context managers
• No eval/exec usage
• No shell command injection vectors

This security analysis was performed based on static code review. Dynamic testing (penetration testing, fuzzing) is recommended for production deployments.