LowFix available
curl — security advisory
curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.
- Products
- curl
- Affected versions
- Not specified
- Fixed versions
- 7.76.0-r0
- CVEs
- CVE-2021-22890
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:02 UTC · Revision 1
Source evidence
curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.
osv:ALPINE-CVE-2021-22890
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
curl
Fixed versions: 7.76.0-r0
Complete source record
{
"id": "ab58a3c6bcf72702aa1d6c79bfd188da9f0b241eef4f52be7936ef11927e22f4",
"url": "https://osv.dev/vulnerability/ALPINE-CVE-2021-22890",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "ALPINE-CVE-2021-22890",
"summary": "curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly \"short-cut\" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.",
"evidence": "osv:ALPINE-CVE-2021-22890",
"products": [
{
"name": {
"value": "curl",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/7/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/8/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/8/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/9/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/9/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/10/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/10/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/11/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/11/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "curl",
"evidence": "/affected/12/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.76.0-r0",
"evidence": "/affected/12/ranges"
}
],
"affected_versions": []
}
],
"severity": "low",
"structured": {
"id": "ALPINE-CVE-2021-22890",
"aliases": [
"ALPINE-CVE-2021-22890"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.12"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.13"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.14"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.15"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.16"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.17"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.18"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.19"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.20"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.21"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.22"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.23"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.76.0-r0"
}
]
}
],
"package": {
"name": "curl",
"purl": "pkg:apk/alpine/curl?arch=source",
"ecosystem": "Alpine:v3.24"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-22890.json"
},
"ecosystem_specific": {}
}
],
"modified": "2026-10-23T17:17:56.150332649Z",
"provider": "osv",
"upstream": [
"CVE-2021-22890"
],
"references": [
"https://security.alpinelinux.org/vuln/CVE-2021-22890"
]
},
"related_cves": [
{
"value": "CVE-2021-22890",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 415303,
"published_at": "2021-04-01T18:15:12.917+00:00"
}