CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
Percentile
60.7%
A specially crafted value of the Sec-Websocket-Protocol
header can be used to significantly slow down a ws server.
for (const length of [1000, 2000, 4000, 8000, 16000, 32000]) {
const value = 'b' + ' '.repeat(length) + 'x';
const start = process.hrtime.bigint();
value.trim().split(/ *, */);
const end = process.hrtime.bigint();
console.log('length = %d, time = %f ns', length, end - start);
}
The vulnerability was fixed in [email protected] (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff) and backported to [email protected] (https://github.com/websockets/ws/commit/78c676d2a1acefbc05292e9f7ea0a9457704bf1b) and [email protected] (https://github.com/websockets/ws/commit/76d47c1479002022a3e4357b3c9f0e23a68d4cd2).
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
and/or the maxHeaderSize
options.
The vulnerability was responsibly disclosed along with a fix in private by Robert McLaughlin from University of California, Santa Barbara.
github.com/advisories/GHSA-6fc8-4gx4-v693
github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
github.com/websockets/ws/issues/1895
github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30@%3Ccommits.tinkerpop.apache.org%3E
nvd.nist.gov/vuln/detail/CVE-2021-32640
security.netapp.com/advisory/ntap-20210706-0005/
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
Percentile
60.7%