CVE-2025-69820

Beta9 volume paths can escape the intended object-key prefix

Beam · Beta9 volume storage

First documented disclosure · Review checkpoint

Summary

Normalized traversal segments can produce presigned URLs outside the selected volume.

Severity and exploitation evidence

Medium · 6.0/10 · CVSS 3.1. Severity source.

Exploitation not established: Researcher proof of concept and maintainer regression tests; malicious exploitation is not established.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

joinCleanPath combines user paths with storage prefixes without enforcing the resulting volume boundary.

Conditions required

Authenticated volume access on affected code. Cross-workspace reach requires an older or alternative shared-bucket deployment; a separate workspace bucket does not become another bucket.

Potential impact

Unauthorized object reads or overwrites within the signing credential’s storage authority; no hosted cross-workspace compromise is established.

Affected versions and configurations

CNA names 0.1.521; researcher names 0.1.552. Numbered affected-range discrepancies remain unresolved.

Fix and mitigation status

PR 2017 / d76ba793b94776e6f043878c0245863370aee222 merged October 16; gateway-0.1.820 and worker-0.1.801 release notes explicitly include it.

Practical next steps

Deploy a supported build containing PR 2017, isolate workspace buckets and restrict signing credentials to intended storage prefixes.

Operating lesson

Path normalization must be followed by authorization against the resulting resource.

Evidence and limits

January 22 is public researcher/CNA disclosure; October 16 is the fix. Score is CISA ADP, not a CNA score; its local/high-privilege vector differs from the CNA’s remote wording. The linked AWS PHP advisory is a separate issue, not this fix.

Sources