CVE-2024-8939
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability was found in the ilab model serve component, where improper handling of the best_of parameter in the vllm JSON web API can lead to a Denial of Service (DoS). The API used for LLM-based sentence or chat completion accepts a best_of parameter to return the best completion from several options. When this parameter is set to a large value, the API does not handle timeouts or resource exhaustion properly, allowing an attacker to cause a DoS by consuming excessive system resources. This leads to the API becoming unresponsive, preventing legitimate users from accessing the service.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThe ilab model serve component's vllm JSON web API lacks proper bounds checking on the best_of parameter, which controls how many completions are generated to select the best result. When an attacker supplies an excessively large value, the API attempts to generate all completions without adequate timeout or resource limits, causing resource exhaustion and DoS.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify ilab model serve component is installedLocate the ilab model serve component installation and identify its version by checking package metadata, binary version flag, or installed software inventoryAffected if The ilab model serve component with vllm JSON web API is present in the environment
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Confirm vllm JSON web API is accessibleCheck if the vllm API endpoint is listening and network-accessible (typically port 8000 or configured port); verify the API responds to requestsAffected if The vllm JSON web API is exposed and reachable, allowing external or internal requests
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Inspect best_of parameter configurationReview vllm configuration files or startup parameters for any defined limits on the best_of parameter; check if input validation exists for this parameterAffected if No explicit bounds or limits are defined/configured for the best_of parameter in vllm settings
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Check resource limit settingsExamine vllm or container resource configurations (timeout settings, memory limits, max requests) that would constrain unbounded completion generationAffected if No timeout handling or resource quotas are configured to prevent unbounded best_of processing
A user is affected if the ilab model serve component with vllm JSON web API is running and lacks bounds checking or resource limits on the best_of parameter.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement input validation to cap the best_of parameter to a reasonable maximum value, and add timeout handling and resource quotas to prevent unbounded resource consumption when processing completion requests.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-8939 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-8939 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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