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Vulnerability details: VCID-1xdz-dku3-qqc4
Vulnerability ID VCID-1xdz-dku3-qqc4
Aliases CVE-2021-3672
Summary Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') 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.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3 5.6 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-3672.json
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
epss 0.00055 https://api.first.org/data/v1/epss?cve=CVE-2021-3672
ssvc Track https://bugzilla.redhat.com/show_bug.cgi?id=1988342
ssvc Track https://c-ares.haxx.se/adv_20210810.html
ssvc Track https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
cvssv3.1 8.1 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
archlinux Medium https://security.archlinux.org/AVG-2268
ssvc Track https://security.gentoo.org/glsa/202401-02
ssvc Track https://www.oracle.com/security-alerts/cpujul2022.html
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-3672.json
https://api.first.org/data/v1/epss?cve=CVE-2021-3672
https://bugzilla.redhat.com/show_bug.cgi?id=1988342
https://c-ares.haxx.se/adv_20210810.html
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3672
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
992053 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=992053
ASA-202108-13 https://security.archlinux.org/ASA-202108-13
AVG-2268 https://security.archlinux.org/AVG-2268
CVE-2021-3672 https://nvd.nist.gov/vuln/detail/CVE-2021-3672
GLSA-202401-02 https://security.gentoo.org/glsa/202401-02
GLSA-202405-29 https://security.gentoo.org/glsa/202405-29
RHSA-2021:3280 https://access.redhat.com/errata/RHSA-2021:3280
RHSA-2021:3281 https://access.redhat.com/errata/RHSA-2021:3281
RHSA-2021:3623 https://access.redhat.com/errata/RHSA-2021:3623
RHSA-2021:3638 https://access.redhat.com/errata/RHSA-2021:3638
RHSA-2021:3639 https://access.redhat.com/errata/RHSA-2021:3639
RHSA-2021:3666 https://access.redhat.com/errata/RHSA-2021:3666
RHSA-2022:2043 https://access.redhat.com/errata/RHSA-2022:2043
USN-5034-1 https://usn.ubuntu.com/5034-1/
USN-5034-2 https://usn.ubuntu.com/5034-2/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-3672.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2024-10-15T17:09:33Z/ Found at https://bugzilla.redhat.com/show_bug.cgi?id=1988342
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2024-10-15T17:09:33Z/ Found at https://c-ares.haxx.se/adv_20210810.html
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2024-10-15T17:09:33Z/ Found at https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2024-10-15T17:09:33Z/ Found at https://security.gentoo.org/glsa/202401-02
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2024-10-15T17:09:33Z/ Found at https://www.oracle.com/security-alerts/cpujul2022.html
Exploit Prediction Scoring System (EPSS)
Percentile 0.17144
EPSS Score 0.00055
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:49:06.217691+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/conan/c-ares/CVE-2021-3672.yml 38.0.0