HOMEVULNERABILITIESCVE-2021-32640
MEDIUM

CVE-2021-32640

CWE-400Published: May 25, 2021· Updated: Jun 17, 2026

5.3
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-32640 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Vendors & Products

netapp1 product(s)
e-series performance analyzer
ws_project1 product(s)
ws
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
PATCHhttps://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
PATCHhttps://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
PATCHhttps://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
ADVISORYhttps://security.netapp.com/advisory/ntap-20210706-0005/
ADVISORYhttps://security.netapp.com/advisory/ntap-20210706-0005/

All References (8)

→
https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ffPatch · Third Party Advisory
→
https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693Exploit · Mitigation · Patch · Third Party Advisory
→
https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E
→
https://security.netapp.com/advisory/ntap-20210706-0005/Third Party Advisory
→
https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ffPatch · Third Party Advisory
→
https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693Exploit · Mitigation · Patch · Third Party Advisory
→
https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E
→
https://security.netapp.com/advisory/ntap-20210706-0005/Third Party Advisory

Quick Facts

CVE IDCVE-2021-32640
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-400
CISA KEVNo
Affected2 vendor(s)
PublishedMay 25, 2021

Related CVEs (CWE-400)

CVE-2018-16491
9.8
CVE-2018-16486
9.8
CVE-2018-16489
9.8
CVE-2017-9119
9.8
CVE-2017-1000378
9.8
CVE-2018-16492
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-32640 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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