Skip to content
Fencer Vulns
high 7.7

CVE-2021-23386 json

Remote Memory Exposure

published 2021-05-20 5 y ago modified 2026-06-17 4 mo ago also GHSA-3wcq-x3mq-6r9p , EUVD-2021-0923

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

This affects the package dns-packet before 5.2.2. It creates buffers with allocUnsafe and does not always fill them before forming network packets. This can expose internal application memory over unencrypted network when querying crafted invalid domain names.

Patch / fix

  • npm dns-packet 1.3.2, 5.2.2
  • n/a dns-packet 5.2.2

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-23386 updated cvss 6.3

dns-packet: does not always fill buffers before forming network packets which couls result in Remote Memory Exposure

  • Red Hat OpenShift Service Mesh 2.0 servicemesh-prometheus
    affected: no fix available
  • Red Hat OpenShift Container Platform 4 openshift4/ose-prometheus, openshift4/ose-thanos-rhel8
    affected: no fix planned “Will not fix”
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-rhel8, rhacm2/search-ui-rhel8, rhacm2/kui-web-terminal-rhel8 Red Hat Fuse 7 apicurito apicurito
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.43% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N
GitHub 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L

Affected packages

ecosystem package affected fixed in
npm dns-packet
>=2.0.0, <5.2.2
<1.3.2
5.2.2
1.3.2

Affected products

  • n/a dns-packet

Classification

Weakness
  • CWE-909 Missing Initialization of Resource
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-908 Use of Uninitialized Resource

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.