CVE-2021-32640

MEDIUM
Published May 25, 20215y ago · Modified Jun 17, 20262w ago
5.3 CVSS 3.1
Medium
Find Similar
Published May 25, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

ws is an open source WebSocket client and server library for Node.js. A specially crafted value of the `Sec-Websocket-Protocol` header can be used to significantly slow down a ws server. The vulnerability has been fixed in ws@7.4.6 (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff). In vulnerable versions of ws, the issue can be mitigated by reducing the maximum allowed length of the request headers using the [`--max-http-header-size=size`](https://nodejs.org/api/cli.html#cli_max_http_header_size_size) and/or the [`maxHeaderSize`](https://nodejs.org/api/http.html#http_http_createserver_options_requestlistener) options.

CVSS Details

Base Score
5.3
Exploitability
3.9
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability Low

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 3

VendorProductVersionRange
ws_projectws*≥5.0.0  –  <6.2.2
ws_projectws*≥7.0.0  –  <7.4.6
netappe-series_performance_analyzer*any

References 4

  • github.com https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
    PatchThird Party Advisory
  • github.com https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
    ExploitMitigationPatchThird Party Advisory
  • lists.apache.org https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E
  • security.netapp.com https://security.netapp.com/advisory/ntap-20210706-0005/
    Third Party Advisory

Remediation

  • github.com https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
    PatchThird Party Advisory
  • github.com https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
    ExploitMitigationPatchThird Party Advisory