critical CVSS 9.9

CVE-2025-54381·Python vulnerability

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. In versions 1.4.0 until 1.4.19, the file upload processing system contains an SSRF vulnerability that allows unauthenticated remote attackers to force the server to make arbitrary HTTP requests. The vulnerability stems from the multipart form data and JSON request handlers, which automatically download files from user-provided URLs without validating whether those URLs point to internal network addresses, cloud metadata endpoints, or other restricted resources. The documentation explicitly promotes this URL-based file upload feature, making it an intended design that exposes all deployed services to SSRF attacks by default. Version 1.4.19 contains a patch for the issue.

Severity: critical
Software: Python
Fixed in: 1.4.19
Published: 2025-07-29

Affected versions

From: 1.4.0

Until: 1.4.19

Fixed in: 1.4.19

How to fix this CVE

Update BentoML to version 1.4.19 or later to patch the SSRF vulnerability in the file upload handler. If you cannot upgrade immediately, disable or restrict access to the file upload endpoints by implementing network-level access controls or WAF rules that validate and block requests with suspicious URLs. Audit your deployment logs for evidence of exploitation attempts targeting internal URLs or cloud metadata endpoints.

sudo dnf update python3-bentoml

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

POST|GET request to /upload or /predict endpoints with parameters containing 'url' or 'file_url' field set to internal IP ranges (10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2[0-9]|3[01])\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3}|169\.254\.169\.254|metadata\.google\.internal)

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch.

Block POST/GET requests to file upload endpoints containing `url` or `file_url` parameters that reference private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback addresses (127.0.0.0/8), or cloud metadata endpoints (169.254.169.254, metadata.google.internal, metadata.azure.com). Allow only whitelisted external domains for file downloads.

How to check if you are affected

Run `pip show bentoml | grep Version` to check the installed BentoML version; versions 1.4.0 through 1.4.18 are vulnerable.
Search your application code for multipart form handlers or JSON endpoints that accept `url` or `file_url` parameters without validation.
Check application logs for HTTP requests containing internal IPs (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) or cloud metadata endpoints (169.254.169.254, metadata.google.internal).
Verify the patch by running `pip show bentoml` again and confirming the version is 1.4.19 or higher; also review the BentoML security advisories at https://github.com/bentoml/BentoML/security/advisories/GHSA-mrmq-3q62-6cc8.

FAQ

What is CVE-2025-54381?

CVE-2025-54381 is a Server-Side Request Forgery (SSRF) vulnerability in BentoML's file upload system that allows attackers to make the server fetch arbitrary files from attacker-controlled URLs, potentially exposing internal network resources and cloud metadata.

Is CVE-2025-54381 being actively exploited?

No, CVE-2025-54381 is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available.

What versions of BentoML are affected by CVE-2025-54381?

BentoML versions 1.4.0 through 1.4.18 are affected; version 1.4.19 and later include the security patch.

How do I check if my server is vulnerable to CVE-2025-54381?

Run `pip show bentoml | grep Version` and verify the version number is below 1.4.19; if it is, your deployment is vulnerable and requires immediate patching.

Does Defensia detect CVE-2025-54381?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If BentoML is installed on a monitored server, CVE-2025-54381 will appear in your dashboard with remediation steps.

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References

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