Aqara API cross-account access

Executive summary #

The Aqara Cloud Production API (open-cn.aqara.com/v3.0/open/api) would authorize any valid developer token for access to any account. This is an instance of "CWE-862: Missing Authorization" with an estimated CVSS of CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N (9.6 Critical). When combined with CVE-2026-50082, CVE-50083, and CVE-50085, this can lead to a fully unauthenticated, remote takeover of affected devices.

Technical details #

The production API authenticates each call with an MD5 signature derived from the request:

Sign = MD5(
  "Appid"+appid + "Keyid"+keyid +
  "Nonce"+nonce + "Time"+ts +
  "Content-SHA256"+SHA256(body)
).toUpperCase()

The signing primitive is sound. The flaw is in what it authorizes: any valid developer Appid (CVE-2026-50082 issues these for free to any email) is accepted as authorization to call user-scope endpoints against arbitrary user accounts on the platform. There is no per-account ownership check on the targeted resource.

Further technical details for this issue can be found at https://github.com/xn0tsa/theres-no-place-like-home

Attacker value #

This is step 3 of an attack chain that can converts an unauthenticated developer registration (CVE-2026-50082) plus a scope=all token (CVE-2026-50083) into a full read/write surface against arbitrary Aqara user accounts.

Credit #

These issues were discovered, documented, and disclosed by Sammy Azdoufal. CVE coordination was performed by Tod Beardsley of runZero, Inc.

Timeline #

2026-03-13: Set of issues discovered by the researcher and outreach to the vendor initiated

2026-03-30: Second outreach by the researcher

2026-04-08: Various findings and vulnerabilities remediated by the vendor

2026-04-20: Acknowledged the researcher's reporting

2026-04-20: The vendor stated this issue has been fixed

2026-06-12: This public disclosure (90 days from first contact)

For more details on specific findings and fixes, please see the researcher's website at https://github.com/xn0tsa/theres-no-place-like-home.