CVE-2021-37705

Critical

Description

OneFuzz is an open source self-hosted Fuzzing-As-A-Service platform. Starting with OneFuzz 2.12.0 or greater, an incomplete authorization check allows an authenticated user from any Azure Active Directory tenant to make authorized API calls to a vulnerable OneFuzz instance. To be vulnerable, a OneFuzz deployment must be both version 2.12.0 or greater and deployed with the non-default --multi_tenant_domain option. This can result in read/write access to private data such as software vulnerability and crash information, security testing tools and proprietary code and symbols. Via authorized API calls, this also enables tampering with existing data and unauthorized code execution on Azure compute resources. This issue is resolved starting in release 2.31.0, via the addition of application-level check of the bearer token's `issuer` against an administrator-configured allowlist. As a workaround users can restrict access to the tenant of a deployed OneFuzz instance < 2.31.0 by redeploying in the default configuration, which omits the `--multi_tenant_domain` option.

SeverityCritical
CVSS10.0
Exploit probability—
ProductMicrosoft Onefuzz
PublishedAug 13, 2021
First seenAug 13, 2021

How to fix

Update
  • microsoft onefuzz2.31.0 or later
  • onefuzz2.31.0 or later

Affected products

ProductAffected versionsFixed in
microsoft onefuzz2.12.0 ≤ v < 2.31.02.31.0
onefuzzPyPI2.12.0 ≤ v < 2.31.02.31.0

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CVE-2021-37705 · Microsoft Onefuzz · Dark Radar