Critical
Security advisory
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-22945
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 07:01 UTC · Revision 1
Source evidence
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.
osv:CVE-2021-22945
Complete source record
{
"id": "402503cab3f0da4598276b91a3a558eac894ab194d4b432ac93dd5fefa9c2d1d",
"url": "https://osv.dev/vulnerability/CVE-2021-22945",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-22945",
"summary": "When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.",
"evidence": "osv:CVE-2021-22945",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2021-22945",
"aliases": [
"CURL-CVE-2021-22945",
"CVE-2021-22945"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/curl/curl",
"type": "GIT",
"events": [
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},
{
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}
],
"database_specific": {
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{
"cpe": "cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "7.73.0"
},
{
"last_affected": "7.78.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"curl-7_78_0",
"curl-7_77_0",
"curl-7_76_1",
"curl-7_76_0",
"curl-7_75_0",
"curl-7_74_0",
"curl-7_73_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-22945.json"
}
},
{
"ranges": [
{
"repo": "https://github.com/mysql/mysql-server",
"type": "GIT",
"events": [
{
"introduced": "0"
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{
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{
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{
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}
],
"database_specific": {
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{
"cpe": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "5.7.0"
},
{
"last_affected": "5.7.35"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "8.0.0"
},
{
"last_affected": "8.0.26"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
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"mysql-8.0.26",
"mysql-5.7.35",
"mysql-5.7.32",
"mysql-5.7.31",
"mysql-5.1.4",
"mysql-4.0.4",
"mysql-4.0.2",
"mysql-3.23.36",
"mysql-3.23.33",
"mysql-3.23.32",
"mysql-3.23.31",
"mysql-3.23.30-gamma",
"mysql-3.23.28-gamma",
"mysql-3.23.22-beta"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-22945.json"
}
}
],
"modified": "2026-10-24T10:30:47.416917569Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-389290.html",
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/",
"https://security.gentoo.org/glsa/202212-01",
"https://security.netapp.com/advisory/ntap-20211029-0003/",
"https://support.apple.com/kb/HT213183",
"https://www.debian.org/security/2022/dsa-5197",
"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf",
"https://hackerone.com/reports/1269242",
"https://www.oracle.com/security-alerts/cpuoct2021.html"
],
"provider_metadata": {
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{
"cpes": [
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],
"vendor_product": "apple:macos",
"extracted_events": [
{
"range": [
{
"introduced": "12.0.0"
},
{
"fixed": "12.3"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:siemens:sinec_ins:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:sinec_ins",
"extracted_events": [
{
"range": [
{
"fixed": "1.0.1.1"
}
],
"source": "CPE_RANGE"
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]
},
{
"cpes": [
"cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:*"
],
"vendor_product": "splunk:universal_forwarder",
"extracted_events": [
{
"range": [
{
"introduced": "8.2.0"
},
{
"fixed": "8.2.12"
},
{
"introduced": "9.0.0"
},
{
"fixed": "9.0.6"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "11.0"
},
{
"last_affected": "11.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "33"
},
{
"last_affected": "33"
},
{
"introduced": "35"
},
{
"last_affected": "35"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:*"
],
"vendor_product": "splunk:universal_forwarder",
"extracted_events": [
{
"range": [
{
"introduced": "9.1.0"
},
{
"last_affected": "9.1.0"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2021-22945",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 436538,
"published_at": "2021-09-23T13:15:08.69+00:00"
}