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Fencer Vulns
medium 5.9

CVE-2020-22217 json

Buffer overflow vulnerability in c-ares before 1_16_1 thru 1_17_0 via function ares_parse_soa_reply in ares_parse_soa_reply.c.

published 2023-08-22 3 y ago modified 2026-06-17 4 mo ago also EUVD-2020-14982

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits
0
none known

Summary

Buffer overflow vulnerability in c-ares before 1_16_1 thru 1_17_0 via function ares_parse_soa_reply in ares_parse_soa_reply.c.

Patch / fix

  • c-ares Debian 14, Debian 13, Debian 12 1.17.1-1

debian advisories DEBIAN-CVE-2020-22217

  • c-ares Ubuntu 20.04 LTS 1.15.0-1ubuntu0.4
  • c-ares Ubuntu Pro 16.04 LTS 1.10.0-3ubuntu0.2+esm4
  • c-ares Ubuntu Pro 18.04 LTS 1.14.0-1ubuntu0.2+esm3

ubuntu advisories UBUNTU-CVE-2020-22217

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • c-ares RHEL 8 1.13.0-9.el8_9.1
  • c-ares RHEL 8.8 EUS 1.13.0-6.el8_8.4
  • c-ares RHEL 8.6 EUS 1.13.0-6.el8_6.3

red hat advisories RHSA-2024:0578RHSA-2024:0419RHSA-2023:7207

  • libcares2 SLES for SAP 12 SP5, SLES 12 SP5, SLE Workstation Extension 12 SP5 +1 more 1.9.1-9.18.1

suse advisories SUSE-SU-2023:3690-1

  • c-ares AlmaLinux 8 1.13.0-9.el8_9.1

almalinux advisories ALSA-2023:7207

  • c-ares Rocky Linux 8 1.13.0-9.el8_9.1

rocky linux advisories RLSA-2023:7207

  • python-gevent CBL-Mariner 2.0 21.1.2-1

azure linux advisories AZL-28597

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2020-22217 updated cvss 5.9

c-ares: Heap buffer over read in ares_parse_soa_reply

  • Red Hat Enterprise Linux 6 c-ares Red Hat Enterprise Linux 7 c-ares
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux BaseOS (v. 8) c-ares 1.13.0-9.el8_9.1
    fixed: vendor fix RHSA-2023:7207
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) c-ares 1.13.0-6.el8_6.3
    fixed: vendor fix RHSA-2024:0419
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) c-ares 1.13.0-6.el8_8.4
    fixed: vendor fix RHSA-2024:0578
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-24/ee-supported-rhel9 Red Hat Enterprise Linux 8 npm, nodejs, nodejs-libs, nodejs-nodemon, nodejs-full-i18n, nodejs-packaging, +1 more Red Hat Enterprise Linux 9 npm, c-ares, nodejs, nodejs-libs, nodejs-full-i18n Red Hat Software Collections rh-nodejs14-npm, rh-nodejs14-nodejs, rh-nodejs14-nodejs-full-i18n
    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

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.98% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/c-ares/c-ares/issues/333 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

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.