Search for vulnerabilities
Vulnerability details: VCID-651q-4kpk-bbba
Vulnerability ID VCID-651q-4kpk-bbba
Aliases CVE-2021-20220
GHSA-qjwc-v72v-fq6r
Summary HTTP request smuggling in Undertow A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own. The highest threat from this vulnerability is to data confidentiality and integrity.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3 4.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-20220.json
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
epss 0.0031 https://api.first.org/data/v1/epss?cve=CVE-2021-20220
cvssv3.1 4.8 https://bugzilla.redhat.com/show_bug.cgi?id=1923133
generic_textual MODERATE https://bugzilla.redhat.com/show_bug.cgi?id=1923133
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-qjwc-v72v-fq6r
cvssv3.1 4.8 https://github.com/undertow-io/undertow/commit/9e797b2f99617fdad0471eaa88c711ee7f44605f
generic_textual MODERATE https://github.com/undertow-io/undertow/commit/9e797b2f99617fdad0471eaa88c711ee7f44605f
cvssv2 5.8 https://nvd.nist.gov/vuln/detail/CVE-2021-20220
cvssv3.1 4.8 https://nvd.nist.gov/vuln/detail/CVE-2021-20220
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2021-20220
cvssv3.1 4.8 https://security.netapp.com/advisory/ntap-20220210-0013
generic_textual MODERATE https://security.netapp.com/advisory/ntap-20220210-0013
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-20220.json
https://api.first.org/data/v1/epss?cve=CVE-2021-20220
https://bugzilla.redhat.com/show_bug.cgi?id=1923133
https://github.com/undertow-io/undertow/commit/9e797b2f99617fdad0471eaa88c711ee7f44605f
https://nvd.nist.gov/vuln/detail/CVE-2021-20220
https://security.netapp.com/advisory/ntap-20220210-0013
https://security.netapp.com/advisory/ntap-20220210-0013/
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:linux:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:linux:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:windows:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:windows:*:*
cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:undertow:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:redhat:undertow:*:*:*:*:*:*:*:*
GHSA-qjwc-v72v-fq6r https://github.com/advisories/GHSA-qjwc-v72v-fq6r
RHSA-2021:0872 https://access.redhat.com/errata/RHSA-2021:0872
RHSA-2021:0873 https://access.redhat.com/errata/RHSA-2021:0873
RHSA-2021:0874 https://access.redhat.com/errata/RHSA-2021:0874
RHSA-2021:0885 https://access.redhat.com/errata/RHSA-2021:0885
RHSA-2021:0974 https://access.redhat.com/errata/RHSA-2021:0974
RHSA-2021:2210 https://access.redhat.com/errata/RHSA-2021:2210
RHSA-2021:2755 https://access.redhat.com/errata/RHSA-2021:2755
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-20220.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: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://bugzilla.redhat.com/show_bug.cgi?id=1923133
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: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://github.com/undertow-io/undertow/commit/9e797b2f99617fdad0471eaa88c711ee7f44605f
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: AV:N/AC:M/Au:N/C:P/I:P/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-20220
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-20220
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: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://security.netapp.com/advisory/ntap-20220210-0013
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
Exploit Prediction Scoring System (EPSS)
Percentile 0.53596
EPSS Score 0.0031
Published At June 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-01T12:19:43.738018+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/06/GHSA-qjwc-v72v-fq6r/GHSA-qjwc-v72v-fq6r.json 36.1.3