T09 · Insecure Skill Coding Practices
Warning
- Location
scripts/png_analyzer.py:41- Finding
Unbounded Processing of Attacker-Controlled PNG Files Enables Resource Exhaustion
- Content
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I', data[pos:pos+4])[0] chunk_type = data[pos+4:pos+8].decode('ascii', errors='replace') chunk_data = data[pos+8:pos+8+length] ``` ```python # Open and decompress the image img = Image.open(io.BytesIO(data)) ``` ```python # Process every column in as many as eight complete rows width, height = img.size pixels = img.load() # Extract LSBs from the first eight rows lsb_rows = {} for row in range(min(8, height)): R, G, B = [], [], [] for col in range(width): px = pixels[col, row] if isinstance(px, int): px = (px, px, px) r, g, b = px[:3] R.append(str(r & 1)) G.append(str(g & 1)) B.append(str(b & 1)) lsb_rows[row] = {'R': R, 'G': G, 'B': B} ``` ```python # Repeatedly expand and process row data under all 15 patterns for name, func in patterns: seq = func(R, G, B) binstr = ''.join(seq) # Decode into characters decs = [] chars = [] for i in range(0, len(binstr), 8): byte = binstr[i:i+8] if len(byte) == 8: dec = int(byte, 2) decs.append(dec) if 32 <= dec <= 126: chars.append(chr(dec)) else: chars.append('.') row_patterns.append({ 'name': name, 'binstr': binstr[:80] + ('...' if len(binstr) > 80 else ''), 'decs': decs[:20], 'chars': ''.join(chars) }) ``` ### Technical Analysis The analyzer accepts a user-selected PNG path and processes the f ...[truncated 2472 chars]- Remediation
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