c-ares: Missing input validation of host names may lead to domain hijacking
Published Nov 23, 2021
5.6
MEDIUMCVSS 3.1
EPSS 2.81%
Description
A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability.
Affected products
- Vendor n/a Product C-Ares Defaultn/a
- Version c-ares 1.17.2StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | C-Ares | n/a |
|
Configuration 1
- ≥ 1.0.0 · < 1.17.2
Configuration 2
- 33
- 34
Configuration 3
- 7.0
- 7.7
- 8.0
- 1
- 7.7
- 8.1
- 8.2
- 8.4
- 8.0
- 8.1
- 8.2
- 8.4
- 8.0
- 8.1
- 8.2
- 8.4
- 8.2
- 8.4
- 8.2
- 8.4
- 8.1
- 8.2
- 8.4
- 8.4
- 1
Configuration 4
- < 1.0.1.1
Configuration 5
No data.
Red Hat Enterprise Linux 8
c-ares-0:1.13.0-6.el8
Fixed · RHSA-2022:2043
Red Hat Enterprise Linux 8
nodejs:12-8040020210817133458.522a0ee4
Fixed · RHSA-2021:3623
Red Hat Enterprise Linux 8
nodejs:14-8040020210817165654.522a0ee4
Fixed · RHSA-2021:3666
Red Hat Enterprise Linux 8.1 Extended Update Support
nodejs:12-8010020210817113128.c27ad7f8
Fixed · RHSA-2021:3639
Red Hat Enterprise Linux 8.2 Extended Update Support
nodejs:12-8020020210817125332.4cda2c84
Fixed · RHSA-2021:3638
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-nodejs12-nodejs-0:12.22.5-1.el7
Fixed · RHSA-2021:3281
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-nodejs12-nodejs-nodemon-0:2.0.3-5.el7
Fixed · RHSA-2021:3281
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-nodejs14-nodejs-0:14.17.5-1.el7
Fixed · RHSA-2021:3280
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS
rh-nodejs12-nodejs-0:12.22.5-1.el7
Fixed · RHSA-2021:3281
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS
rh-nodejs12-nodejs-nodemon-0:2.0.3-5.el7
Fixed · RHSA-2021:3281
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS
rh-nodejs14-nodejs-0:14.17.5-1.el7
Fixed · RHSA-2021:3280
Red Hat Enterprise Linux 6
c-ares
Out of support scope
Red Hat Enterprise Linux 7
c-ares
Out of support scope
Red Hat Enterprise Linux 8
nodejs:16/nodejs
Not affected
Red Hat Enterprise Linux 9
c-ares
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | c-ares-0:1.13.0-6.el8 | Fixed | RHSA-2022:2043 |
| Red Hat Enterprise Linux 8 | nodejs:12-8040020210817133458.522a0ee4 | Fixed | RHSA-2021:3623 |
| Red Hat Enterprise Linux 8 | nodejs:14-8040020210817165654.522a0ee4 | Fixed | RHSA-2021:3666 |
| Red Hat Enterprise Linux 8.1 Extended Update Support | nodejs:12-8010020210817113128.c27ad7f8 | Fixed | RHSA-2021:3639 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | nodejs:12-8020020210817125332.4cda2c84 | Fixed | RHSA-2021:3638 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-nodejs12-nodejs-0:12.22.5-1.el7 | Fixed | RHSA-2021:3281 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-nodejs12-nodejs-nodemon-0:2.0.3-5.el7 | Fixed | RHSA-2021:3281 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-nodejs14-nodejs-0:14.17.5-1.el7 | Fixed | RHSA-2021:3280 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS | rh-nodejs12-nodejs-0:12.22.5-1.el7 | Fixed | RHSA-2021:3281 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS | rh-nodejs12-nodejs-nodemon-0:2.0.3-5.el7 | Fixed | RHSA-2021:3281 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS | rh-nodejs14-nodejs-0:14.17.5-1.el7 | Fixed | RHSA-2021:3280 |
| Red Hat Enterprise Linux 6 | c-ares | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | c-ares | Out of support scope | n/a |
| Red Hat Enterprise Linux 8 | nodejs:16/nodejs | Not affected | n/a |
| Red Hat Enterprise Linux 9 | c-ares | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Oct 15, 2024 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (13 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.81% (0.02814) | 86.04th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.62% (0.02617) | 83.39th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.07% (0.00067) | 17.97th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.26% (0.00260) | 66.34th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.16% (0.00157) | 51.56th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.13% (0.00126) | 45.48th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.95% (0.00954) | 32.50th | v2 (v2022.01.01) |
| Mar 9, 2022 | 5.74% (0.05736) | 77.57th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.50% (0.04499) | 74.08th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.74% (0.02742) | 63.06th | v5 (v2026.06.15) |
| Jan 6, 2022 | 2.74% (0.02742) | 62.72th | v1 |
| Nov 24, 2021 | 0.62% (0.00624) | 45.76th | v1 |
References (8)
- https://access.redhat.com/security/cve/CVE-2021-3672 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1988342 Issue TrackingThird Party Advisory
- https://c-ares.haxx.se/adv_20210810.html ExploitPatchVendor Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf PatchThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2021-3672
- https://security.gentoo.org/glsa/202401-02 vendor-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-3672
- https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2021-3672 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1988342 | Issue TrackingThird Party Advisory | |
| https://c-ares.haxx.se/adv_20210810.html | ExploitPatchVendor Advisory | |
| https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf | PatchThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2021-3672 | ||
| https://security.gentoo.org/glsa/202401-02 | vendor-advisory | |
| https://www.cve.org/CVERecord?id=CVE-2021-3672 | ||
| https://www.oracle.com/security-alerts/cpujul2022.html | Third Party Advisory |
Change history (0)
No recorded changes yet.