CVE-2021-39242 (GCVE-0-2021-39242)
Vulnerability from cvelistv5 – Published: 2021-08-17 18:33 – Updated: 2024-08-04 02:06
VLAI
EPSS
VEX
Summary
An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.
Severity
7.5 (High)
CWE
- n/a
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://www.mail-archive.com/haproxy%40formilux.o… | x_refsource_MISC |
| https://git.haproxy.org/?p=haproxy.git%3Ba=commit… | x_refsource_MISC |
| https://www.debian.org/security/2021/dsa-4960 | vendor-advisoryx_refsource_DEBIAN |
| https://lists.fedoraproject.org/archives/list/pac… | vendor-advisoryx_refsource_FEDORA |
| https://lists.fedoraproject.org/archives/list/pac… | vendor-advisoryx_refsource_FEDORA |
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-04T02:06:40.808Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_refsource_MISC",
"x_transferred"
],
"url": "https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html"
},
{
"tags": [
"x_refsource_MISC",
"x_transferred"
],
"url": "https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1"
},
{
"name": "DSA-4960",
"tags": [
"vendor-advisory",
"x_refsource_DEBIAN",
"x_transferred"
],
"url": "https://www.debian.org/security/2021/dsa-4960"
},
{
"name": "FEDORA-2021-e6557245e8",
"tags": [
"vendor-advisory",
"x_refsource_FEDORA",
"x_transferred"
],
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/"
},
{
"name": "FEDORA-2021-3ab4512c98",
"tags": [
"vendor-advisory",
"x_refsource_FEDORA",
"x_transferred"
],
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/"
}
],
"title": "CVE Program Container"
}
],
"cna": {
"affected": [
{
"product": "n/a",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled."
}
],
"problemTypes": [
{
"descriptions": [
{
"description": "n/a",
"lang": "en",
"type": "text"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2021-08-26T23:06:24.000Z",
"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"shortName": "mitre"
},
"references": [
{
"tags": [
"x_refsource_MISC"
],
"url": "https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html"
},
{
"tags": [
"x_refsource_MISC"
],
"url": "https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1"
},
{
"name": "DSA-4960",
"tags": [
"vendor-advisory",
"x_refsource_DEBIAN"
],
"url": "https://www.debian.org/security/2021/dsa-4960"
},
{
"name": "FEDORA-2021-e6557245e8",
"tags": [
"vendor-advisory",
"x_refsource_FEDORA"
],
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/"
},
{
"name": "FEDORA-2021-3ab4512c98",
"tags": [
"vendor-advisory",
"x_refsource_FEDORA"
],
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/"
}
],
"x_legacyV4Record": {
"CVE_data_meta": {
"ASSIGNER": "cve@mitre.org",
"ID": "CVE-2021-39242",
"STATE": "PUBLIC"
},
"affects": {
"vendor": {
"vendor_data": [
{
"product": {
"product_data": [
{
"product_name": "n/a",
"version": {
"version_data": [
{
"version_value": "n/a"
}
]
}
}
]
},
"vendor_name": "n/a"
}
]
}
},
"data_format": "MITRE",
"data_type": "CVE",
"data_version": "4.0",
"description": {
"description_data": [
{
"lang": "eng",
"value": "An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled."
}
]
},
"problemtype": {
"problemtype_data": [
{
"description": [
{
"lang": "eng",
"value": "n/a"
}
]
}
]
},
"references": {
"reference_data": [
{
"name": "https://www.mail-archive.com/haproxy@formilux.org/msg41041.html",
"refsource": "MISC",
"url": "https://www.mail-archive.com/haproxy@formilux.org/msg41041.html"
},
{
"name": "https://git.haproxy.org/?p=haproxy.git;a=commit;h=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1",
"refsource": "MISC",
"url": "https://git.haproxy.org/?p=haproxy.git;a=commit;h=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1"
},
{
"name": "DSA-4960",
"refsource": "DEBIAN",
"url": "https://www.debian.org/security/2021/dsa-4960"
},
{
"name": "FEDORA-2021-e6557245e8",
"refsource": "FEDORA",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/"
},
{
"name": "FEDORA-2021-3ab4512c98",
"refsource": "FEDORA",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/"
}
]
}
}
}
},
"cveMetadata": {
"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"assignerShortName": "mitre",
"cveId": "CVE-2021-39242",
"datePublished": "2021-08-17T18:33:00.000Z",
"dateReserved": "2021-08-17T00:00:00.000Z",
"dateUpdated": "2024-08-04T02:06:40.808Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-39242",
"date": "2026-09-14",
"epss": "0.02341",
"percentile": "0.82674"
},
"fkie_nvd": {
"configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"2.2.0\", \"versionEndExcluding\": \"2.2.16\", \"matchCriteriaId\": \"B8A35038-8767-48F3-B81F-81FCD0B31D32\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"2.3.0\", \"versionEndExcluding\": \"2.3.13\", \"matchCriteriaId\": \"040439D6-C0FC-4550-884E-1B3FB396A5DF\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"2.4.0\", \"versionEndExcluding\": \"2.4.3\", \"matchCriteriaId\": \"88FF602C-41E1-4569-B09B-161BB7C85891\"}]}]}, {\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"FA6FEEC2-9F11-4643-8827-749718254FED\"}]}]}, {\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"E460AA51-FCDA-46B9-AE97-E6676AA5E194\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"A930E247-0B43-43CB-98FF-6CE7B8189835\"}]}]}]",
"descriptions": "[{\"lang\": \"en\", \"value\": \"An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.\"}, {\"lang\": \"es\", \"value\": \"Se ha detectado un problema en HAProxy versiones 2.2 anteriores a 2.2.16, versiones 2.3 anteriores a 2.3.13 y versiones 2.4 anteriores a 2.4.3. Puede conllevar a una situaci\\u00f3n con un encabezado HTTP Host controlada por un atacante, porque es manejado inapropiadamente un desajuste entre Host y autoridad.\"}]",
"id": "CVE-2021-39242",
"lastModified": "2024-11-21T06:18:59.860",
"metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"HIGH\", \"availabilityImpact\": \"NONE\"}, \"exploitabilityScore\": 3.9, \"impactScore\": 3.6}], \"cvssMetricV2\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"2.0\", \"vectorString\": \"AV:N/AC:L/Au:N/C:N/I:P/A:N\", \"baseScore\": 5.0, \"accessVector\": \"NETWORK\", \"accessComplexity\": \"LOW\", \"authentication\": \"NONE\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"PARTIAL\", \"availabilityImpact\": \"NONE\"}, \"baseSeverity\": \"MEDIUM\", \"exploitabilityScore\": 10.0, \"impactScore\": 2.9, \"acInsufInfo\": false, \"obtainAllPrivilege\": false, \"obtainUserPrivilege\": false, \"obtainOtherPrivilege\": false, \"userInteractionRequired\": false}]}",
"published": "2021-08-17T19:15:08.320",
"references": "[{\"url\": \"https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1\", \"source\": \"cve@mitre.org\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/\", \"source\": \"cve@mitre.org\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/\", \"source\": \"cve@mitre.org\"}, {\"url\": \"https://www.debian.org/security/2021/dsa-4960\", \"source\": \"cve@mitre.org\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html\", \"source\": \"cve@mitre.org\"}, {\"url\": \"https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://www.debian.org/security/2021/dsa-4960\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}]",
"sourceIdentifier": "cve@mitre.org",
"vulnStatus": "Modified",
"weaknesses": "[{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-755\"}]}]"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2021-39242\",\"sourceIdentifier\":\"cve@mitre.org\",\"published\":\"2021-08-17T19:15:08.320\",\"lastModified\":\"2024-11-21T06:18:59.860\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.\"},{\"lang\":\"es\",\"value\":\"Se ha detectado un problema en HAProxy versiones 2.2 anteriores a 2.2.16, versiones 2.3 anteriores a 2.3.13 y versiones 2.4 anteriores a 2.4.3. Puede conllevar a una situaci\u00f3n con un encabezado HTTP Host controlada por un atacante, porque es manejado inapropiadamente un desajuste entre Host y autoridad.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:L/Au:N/C:N/I:P/A:N\",\"baseScore\":5.0,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"LOW\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":10.0,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-755\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.2.0\",\"versionEndExcluding\":\"2.2.16\",\"matchCriteriaId\":\"B8A35038-8767-48F3-B81F-81FCD0B31D32\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.3.0\",\"versionEndExcluding\":\"2.3.13\",\"matchCriteriaId\":\"040439D6-C0FC-4550-884E-1B3FB396A5DF\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.4.0\",\"versionEndExcluding\":\"2.4.3\",\"matchCriteriaId\":\"88FF602C-41E1-4569-B09B-161BB7C85891\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"FA6FEEC2-9F11-4643-8827-749718254FED\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"E460AA51-FCDA-46B9-AE97-E6676AA5E194\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"A930E247-0B43-43CB-98FF-6CE7B8189835\"}]}]}],\"references\":[{\"url\":\"https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://www.debian.org/security/2021/dsa-4960\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://www.debian.org/security/2021/dsa-4960\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2025-11-21T15:54:07+00:00",
"cve": "CVE-2021-39242",
"id": "CVE-2021-39242",
"initial_release_date": "2021-08-17T00:00:00+00:00",
"product_status:fixed": "11",
"product_status:known_affected": "2",
"product_status:known_not_affected": "76",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "haproxy: it can lead to a situation with an attacker-controlled HTTP Host header because a mismatch between Host and authority is mishandled",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-39242.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-08-22T17:05:22Z",
"cve": "CVE-2021-39242",
"id": "CVE-2021-39242",
"initial_release_date": "2023-02-15T03:38:19Z",
"product_status:known_not_affected": "15",
"product_status:recommended": "7",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2021-39242",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-39242.json",
"version": "16"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Loading…
Loading…