deepstream: PATCH_MULTI action bypasses Valve permission system allowing unauthorized record writes

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deepstream is a server that allows clients and backend services to sync data, send messages and make rpcs at scale. From 10.1.0 until 10.1.1, src/services/permission/valve/rules-map.ts omits RECORD_ACTION.PATCH_MULTI from RULES_MAP. When an authenticated user sends a PATCH_MULTI record operation while permission.type is config, getRulesForMessage returns a null rule specification and ConfigPermission.canPerformAction treats the missing specification as an unconditional allow instead of applying RULE_TYPES.WRITE. Any authenticated user can therefore modify arbitrary protected records, corrupt application state, or cause service disruption; deployments using the default permission type none already allow all operations and are not additionally affected. This issue is fixed in version 10.1.1.

Source published

21 Sep 2026 16:59:22 UTC

Source modified

21 Sep 2026 17:59:34 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

deepstream is a server that allows clients and backend services to sync data, send messages and make rpcs at scale. From 10.1.0 until 10.1.1, src/services/permission/valve/rules-map.ts omits RECORD_ACTION.PATCH_MULTI from RULES_MAP. When an authenticated user sends a PATCH_MULTI record operation while permission.type is config, getRulesForMessage returns a null rule specification and ConfigPermission.canPerformAction treats the missing specification as an unconditional allow instead of applying RULE_TYPES.WRITE. Any authenticated user can therefore modify arbitrary protected records, corrupt application state, or cause service disruption; deployments using the default permission type none already allow all operations and are not additionally affected. This issue is fixed in version 10.1.1.

Source published

Sep 21, 2026, 4:59:22 PM (timezone not stated)

Source modified

Sep 21, 2026, 5:59:34 PM (timezone not stated)

Observed here

11 Nov 2026 15:05:34 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

deepstream is a server that allows clients and backend services to sync data, send messages and make rpcs at scale. From 10.1.0 until 10.1.1, src/services/permission/valve/rules-map.ts omits RECORD_ACTION.PATCH_MULTI from RULES_MAP. When an authenticated user sends a PATCH_MULTI record operation while permission.type is config, getRulesForMessage returns a null rule specification and ConfigPermission.canPerformAction treats the missing specification as an unconditional allow instead of applying RULE_TYPES.WRITE. Any authenticated user can therefore modify arbitrary protected records, corrupt application state, or cause service disruption; deployments using the default permission type none already allow all operations and are not additionally affected. This issue is fixed in version 10.1.1.

Source published

21 Sep 2026 17:17:38 UTC

Source modified

24 Sep 2026 21:25:27 UTC

Observed here

25 Oct 2026 14:19:28 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

## Summary The `RECORD_ACTION.PATCH_MULTI` action is not registered in the Valve permission system's `RULES_MAP` (`src/services/permission/valve/rules-map.ts`). When `ConfigPermission.canPerformAction()` is called for a PATCH_MULTI message, `getRulesForMessage()` returns `null` because the action is missing from the map. This triggers an unconditional allow (`callback(..., null, true)`), completely bypassing all configured Valve permission rules. Any authenticated user — regardless of their configured permissions — can write arbitrary data to any record using the PATCH_MULTI action. ## Root Cause In `src/services/permission/valve/rules-map.ts` lines 38-54, the `RULES_MAP[TOPIC.RECORD].actions` dictionary maps record actions to permission rule types. The actions registered include: SUBSCRIBE, SUBSCRIBEANDHEAD, SUBSCRIBEANDREAD, READ, HEAD, LISTEN, CREATE, UPDATE, PATCH, NOTIFY, DELETE, ERASE. However, `RECORD_ACTION.PATCH_MULTI` is **absent** from this map. When `getRulesForMessage()` at line 86-99 encounters an action not in the map, it returns `null`. In `config-permission.ts` at line 88-93, when `ruleSpecification === null`, the callback is invoked with `true` (allow) unconditionally. ## Attack Chain 1. Attacker authenticates with any valid credentials (even a minimal-privilege user) 2. Attacker sends a WebSocket message: `{topic: RECORD, action: PATCH_MULTI, name: "admin/secret-record", parsedData: [{path: "role", data: "admin"}]}` 3. `message-processor.ts:68` invokes permission check 4. `config-permission.ts:89` → `getRulesForMessage()` returns `null` for PATCH_MULTI 5. `config-permission.ts:92` → unconditional ALLOW 6. Record transition applies the operations — arbitrary record is modified ## Impact - **Complete Valve permission bypass for record writes** — all configured permission rules are irrelevant - Any authenticated user can overwrite any record, including admin-only records - Mass record overwrites can destroy application state, corrupt sessions, cause service outage - Only exploitable when `permission.type` is set to `config` (Valve) — the recommended production configuration per deepstream documentation - Default permission type `none` (OpenPermission) allows everything already, so default deployments are unaffected <details><summary>Proof of Concept</summary> ```javascript // Connect as a minimal-privilege user const { DeepstreamClient } = require('@deepstream/client'); const client = new DeepstreamClient('localhost:6020'); await client.login({ username: 'restricted-user', password: 'password' }); // This should be blocked by Valve permissions but isn't: // Send raw PATCH_MULTI message to bypass all permission rules const connection = client.getConnection(); connection.sendMessage({ topic: 0x52, // TOPIC.RECORD action: 0x50, // RECORD_ACTION.PATCH_MULTI (check actual enum value) name: 'admin/protected-record', parsedData: [ { path: 'permissions', data: 'admin' }, { path: 'secret', data: 'overwritten' } ] }); ``` </details> ## Suggested Fix Add `PATCH_MULTI` to the RULES_MAP in `src/services/permission/valve/rules-map.ts`: ```typescript [RECORD_ACTION.PATCH_MULTI]: RULE_TYPES.WRITE, ``` This maps PATCH_MULTI operations to the same WRITE permission rule that governs UPDATE and PATCH. ## Affected Versions All versions that include PATCH_MULTI support with the Valve (ConfigPermission) permission system. The PATCH_MULTI action was added in commit `82ffa8119d8f4a8242ac5c3507469a22de746b65` but was never registered in RULES_MAP. ## Credit Vulnerability discovered by Zhixi "Jace" Sun of ASM/VI at TikTok.

Source published

22 Sep 2026 19:56:34 UTC

Source modified

22 Sep 2026 20:15:05 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Publisher rating · HIGH