vulnerability / NVI-00016435 / Revision 1
node-opcua missing nonce verification in UserNameIdentityToken authentication
GitHub lists this reviewed advisory for node-opcua. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.7 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
node-opcua
source listed<= 2.165.0
**Summary** A missing nonce verification in the UserNameIdentityToken authentication handler allows an unauthenticated remote attacker to forge a password token that extracts as an empty string, and to replay captured authentication tokens across sessions. **Affected versions:** <= 2.165.0 **Tested version:** 2.165.0 **CVSS Score:** 8.1 (High) **CVSS Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L **CWE:** CWE-347 Improper Verification of Cryptographic Signature --- **Root Cause** In `packages/node-opcua-server/source/opcua_server.ts` at line 1886-1887, after RSA-OAEP decrypting the UserNameIdentityToken password blob, the server reads a 4-byte little-endian length field and extracts `buff[4 : 4+length]` as the password. It never verifies that the trailing bytes equal `session.nonce`. This has two consequences: 1. **Forged empty password:** An attacker who retrieves the server's public key via an unauthenticated `GetEndpoints` call can craft a token where the 4-byte length field equals `serverNonce.length` (32). The server computes `length = 32 - 32 = 0` and calls `isValidUser(username, "")`. Any account that accepts an empty password is compromised. 2. **Unconditiona
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-mq36-523m-x7vv ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.