CVE-2021-4097 (GCVE-0-2021-4097)
Vulnerability from cvelistv5 – Published: 2021-12-11 23:30 – Updated: 2024-08-03 17:16
VLAI
EPSS
VEX
Title
CRLF Injection in phpservermon/phpservermon
Summary
phpservermon is vulnerable to Improper Neutralization of CRLF Sequences
Severity
6.3 (Medium)
CWE
- CWE-93 - Improper Neutralization of CRLF Sequences
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://huntr.dev/bounties/d617ced7-be06-4e34-9db… | x_refsource_CONFIRM |
| https://github.com/phpservermon/phpservermon/comm… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| phpservermon | phpservermon/phpservermon |
Affected:
unspecified , < 3.6.0
(custom)
|
guessed |
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-03T17:16:04.220Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_refsource_CONFIRM",
"x_transferred"
],
"url": "https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43"
},
{
"tags": [
"x_refsource_MISC",
"x_transferred"
],
"url": "https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4"
}
],
"title": "CVE Program Container"
}
],
"cna": {
"affected": [
{
"product": "phpservermon/phpservermon",
"vendor": "phpservermon",
"versions": [
{
"lessThan": "3.6.0",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "phpservermon is vulnerable to Improper Neutralization of CRLF Sequences"
}
],
"metrics": [
{
"cvssV3_0": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L",
"version": "3.0"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-93",
"description": "CWE-93 Improper Neutralization of CRLF Sequences",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2021-12-11T23:30:10.000Z",
"orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
"shortName": "@huntrdev"
},
"references": [
{
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43"
},
{
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4"
}
],
"source": {
"advisory": "d617ced7-be06-4e34-9db0-63d45c003a43",
"discovery": "EXTERNAL"
},
"title": "CRLF Injection in phpservermon/phpservermon",
"x_legacyV4Record": {
"CVE_data_meta": {
"ASSIGNER": "security@huntr.dev",
"ID": "CVE-2021-4097",
"STATE": "PUBLIC",
"TITLE": "CRLF Injection in phpservermon/phpservermon"
},
"affects": {
"vendor": {
"vendor_data": [
{
"product": {
"product_data": [
{
"product_name": "phpservermon/phpservermon",
"version": {
"version_data": [
{
"version_affected": "\u003c",
"version_value": "3.6.0"
}
]
}
}
]
},
"vendor_name": "phpservermon"
}
]
}
},
"data_format": "MITRE",
"data_type": "CVE",
"data_version": "4.0",
"description": {
"description_data": [
{
"lang": "eng",
"value": "phpservermon is vulnerable to Improper Neutralization of CRLF Sequences"
}
]
},
"impact": {
"cvss": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L",
"version": "3.0"
}
},
"problemtype": {
"problemtype_data": [
{
"description": [
{
"lang": "eng",
"value": "CWE-93 Improper Neutralization of CRLF Sequences"
}
]
}
]
},
"references": {
"reference_data": [
{
"name": "https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43",
"refsource": "CONFIRM",
"url": "https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43"
},
{
"name": "https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4",
"refsource": "MISC",
"url": "https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4"
}
]
},
"source": {
"advisory": "d617ced7-be06-4e34-9db0-63d45c003a43",
"discovery": "EXTERNAL"
}
}
}
},
"cveMetadata": {
"assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
"assignerShortName": "@huntrdev",
"cveId": "CVE-2021-4097",
"datePublished": "2021-12-11T23:30:10.000Z",
"dateReserved": "2021-12-10T00:00:00.000Z",
"dateUpdated": "2024-08-03T17:16:04.220Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-4097",
"date": "2026-09-17",
"epss": "0.00843",
"percentile": "0.56237"
},
"fkie_nvd": {
"configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:phpservermonitor:php_server_monitor:*:*:*:*:*:*:*:*\", \"versionEndExcluding\": \"3.6.0\", \"matchCriteriaId\": \"9B2188E1-0FA7-40B8-9AE7-52E50B0312CC\"}]}]}]",
"descriptions": "[{\"lang\": \"en\", \"value\": \"phpservermon is vulnerable to Improper Neutralization of CRLF Sequences\"}, {\"lang\": \"es\", \"value\": \"phpservermon es vulnerable a una Neutralizaci\\u00f3n Inapropiada de Secuencias CRLF\"}]",
"id": "CVE-2021-4097",
"lastModified": "2024-11-21T06:36:53.713",
"metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N\", \"baseScore\": 5.4, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"REQUIRED\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"LOW\", \"integrityImpact\": \"LOW\", \"availabilityImpact\": \"NONE\"}, \"exploitabilityScore\": 2.8, \"impactScore\": 2.5}], \"cvssMetricV30\": [{\"source\": \"security@huntr.dev\", \"type\": \"Secondary\", \"cvssData\": {\"version\": \"3.0\", \"vectorString\": \"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L\", \"baseScore\": 6.3, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"REQUIRED\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"LOW\", \"integrityImpact\": \"LOW\", \"availabilityImpact\": \"LOW\"}, \"exploitabilityScore\": 2.8, \"impactScore\": 3.4}], \"cvssMetricV2\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"2.0\", \"vectorString\": \"AV:N/AC:M/Au:N/C:P/I:P/A:N\", \"baseScore\": 5.8, \"accessVector\": \"NETWORK\", \"accessComplexity\": \"MEDIUM\", \"authentication\": \"NONE\", \"confidentialityImpact\": \"PARTIAL\", \"integrityImpact\": \"PARTIAL\", \"availabilityImpact\": \"NONE\"}, \"baseSeverity\": \"MEDIUM\", \"exploitabilityScore\": 8.6, \"impactScore\": 4.9, \"acInsufInfo\": false, \"obtainAllPrivilege\": false, \"obtainUserPrivilege\": false, \"obtainOtherPrivilege\": false, \"userInteractionRequired\": true}]}",
"published": "2021-12-12T00:15:07.743",
"references": "[{\"url\": \"https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4\", \"source\": \"security@huntr.dev\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43\", \"source\": \"security@huntr.dev\", \"tags\": [\"Exploit\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Exploit\", \"Patch\", \"Third Party Advisory\"]}]",
"sourceIdentifier": "security@huntr.dev",
"vulnStatus": "Modified",
"weaknesses": "[{\"source\": \"security@huntr.dev\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-93\"}]}]"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2021-4097\",\"sourceIdentifier\":\"security@huntr.dev\",\"published\":\"2021-12-12T00:15:07.743\",\"lastModified\":\"2026-06-17T04:19:01.750\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"phpservermon is vulnerable to Improper Neutralization of CRLF Sequences\"},{\"lang\":\"es\",\"value\":\"phpservermon es vulnerable a una Neutralizaci\u00f3n Inapropiada de Secuencias CRLF\"}],\"affected\":[{\"source\":\"security@huntr.dev\",\"affectedData\":[{\"vendor\":\"phpservermon\",\"product\":\"phpservermon/phpservermon\",\"versions\":[{\"version\":\"unspecified\",\"lessThan\":\"3.6.0\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N\",\"baseScore\":5.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":2.5}],\"cvssMetricV30\":[{\"source\":\"security@huntr.dev\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.0\",\"vectorString\":\"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L\",\"baseScore\":6.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":2.8,\"impactScore\":3.4}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:M/Au:N/C:P/I:P/A:N\",\"baseScore\":5.8,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":8.6,\"impactScore\":4.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":true}]},\"weaknesses\":[{\"source\":\"security@huntr.dev\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-93\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:phpservermonitor:php_server_monitor:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"3.6.0\",\"matchCriteriaId\":\"9B2188E1-0FA7-40B8-9AE7-52E50B0312CC\"}]}]}],\"references\":[{\"url\":\"https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4\",\"source\":\"security@huntr.dev\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43\",\"source\":\"security@huntr.dev\",\"tags\":[\"Exploit\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Patch\",\"Third Party Advisory\"]}]}}",
"redhat_vex": {
"current_release_date": "2026-03-27T13:32:41+00:00",
"cve": "CVE-2021-4097",
"id": "CVE-2021-4097",
"initial_release_date": "2021-01-01T00:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "CRLF Injection in phpservermon/phpservermon",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-4097.json",
"version": "3"
}
}
}
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…