CriticalFix available
bluez — security advisory
An issue was discovered in gatt-database.c in BlueZ 5.61. A use-after-free can occur when a client disconnects during D-Bus processing of a WriteValue call.
- Products
- bluez
- Affected versions
- 5.35-0ubuntu2, 5.36-0ubuntu1, 5.37-0ubuntu5, 5.37-0ubuntu5.1, 5.37-0ubuntu5.3, 5.37-0ubuntu5.3+esm1, 5.37-0ubuntu5.3+esm2, 5.37-0ubuntu5.3+esm3, 5.37-0ubuntu5.3+esm4, 5.37-0ubuntu5.3+esm5, 5.37-0ubuntu5.3+esm6, 5.46-0ubuntu3, 5.46-0ubuntu4, 5.48-0ubuntu3, 5.48-0ubuntu3.1, 5.48-0ubuntu3.2, 5.48-0ubuntu3.3, 5.48-0ubuntu3.4, 5.48-0ubuntu3.5, 5.50-0ubuntu4, 5.51-0ubuntu1, 5.51-0ubuntu2, 5.52-0ubuntu1, 5.52-0ubuntu2, 5.53-0ubuntu1, 5.53-0ubuntu2, 5.53-0ubuntu3, 5.53-0ubuntu3.1, 5.53-0ubuntu3.2, 5.53-0ubuntu3.3
- Fixed versions
- 5.48-0ubuntu3.6, 5.53-0ubuntu3.4
- CVEs
- CVE-2021-43400
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 10:37 UTC · Revision 1
Source evidence
An issue was discovered in gatt-database.c in BlueZ 5.61. A use-after-free can occur when a client disconnects during D-Bus processing of a WriteValue call.
osv:UBUNTU-CVE-2021-43400
bluez
Fixed versions: Not specified
bluez
Fixed versions: 5.48-0ubuntu3.6
bluez
Fixed versions: 5.53-0ubuntu3.4
Complete source record
{
"id": "689eb69fc918845c45bf616cc31e32712406a0f3fb8ced9c6e31d67784daa726",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-43400",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2021-43400",
"summary": "An issue was discovered in gatt-database.c in BlueZ 5.61. A use-after-free can occur when a client disconnects during D-Bus processing of a WriteValue call.",
"evidence": "osv:UBUNTU-CVE-2021-43400",
"products": [
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
"value": "5.37-0ubuntu5",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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{
"value": "5.48-0ubuntu3.3",
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{
"value": "5.48-0ubuntu3.4",
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{
"value": "5.48-0ubuntu3.5",
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"name": {
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"evidence": "/affected/2/versions"
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{
"value": "5.51-0ubuntu1",
"evidence": "/affected/2/versions"
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{
"value": "5.51-0ubuntu2",
"evidence": "/affected/2/versions"
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{
"value": "5.52-0ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "5.52-0ubuntu2",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu2",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu3",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu3.1",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu3.2",
"evidence": "/affected/2/versions"
},
{
"value": "5.53-0ubuntu3.3",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2021-43400",
"aliases": [
"UBUNTU-CVE-2021-43400"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "bluez",
"purl": "pkg:deb/ubuntu/bluez?arch=source&distro=esm-infra-legacy%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
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"5.36-0ubuntu1",
"5.37-0ubuntu5",
"5.37-0ubuntu5.1",
"5.37-0ubuntu5.3",
"5.37-0ubuntu5.3+esm1",
"5.37-0ubuntu5.3+esm2",
"5.37-0ubuntu5.3+esm3",
"5.37-0ubuntu5.3+esm4",
"5.37-0ubuntu5.3+esm5",
"5.37-0ubuntu5.3+esm6"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43400.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "bluetooth",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "bluez",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "bluez-cups",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "bluez-hcidump",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "bluez-obexd",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "bluez-tests",
"binary_version": "5.37-0ubuntu5.3+esm6"
},
{
"binary_name": "libbluetooth3",
"binary_version": "5.37-0ubuntu5.3+esm6"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.48-0ubuntu3.6"
}
]
}
],
"package": {
"name": "bluez",
"purl": "pkg:deb/ubuntu/bluez?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"5.46-0ubuntu3",
"5.46-0ubuntu4",
"5.48-0ubuntu3",
"5.48-0ubuntu3.1",
"5.48-0ubuntu3.2",
"5.48-0ubuntu3.3",
"5.48-0ubuntu3.4",
"5.48-0ubuntu3.5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43400.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "bluetooth",
"binary_version": "5.48-0ubuntu3.6"
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{
"binary_name": "bluez",
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{
"binary_name": "bluez-cups",
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{
"binary_name": "bluez-hcidump",
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{
"binary_name": "bluez-obexd",
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},
{
"binary_name": "bluez-tests",
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},
{
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"availability": "No subscription required"
}
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{
"ranges": [
{
"type": "ECOSYSTEM",
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},
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"5.51-0ubuntu1",
"5.51-0ubuntu2",
"5.52-0ubuntu1",
"5.52-0ubuntu2",
"5.53-0ubuntu1",
"5.53-0ubuntu2",
"5.53-0ubuntu3",
"5.53-0ubuntu3.1",
"5.53-0ubuntu3.2",
"5.53-0ubuntu3.3"
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"database_specific": {
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},
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{
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},
{
"binary_name": "bluez",
"binary_version": "5.53-0ubuntu3.4"
},
{
"binary_name": "bluez-cups",
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},
{
"binary_name": "bluez-hcidump",
"binary_version": "5.53-0ubuntu3.4"
},
{
"binary_name": "bluez-obexd",
"binary_version": "5.53-0ubuntu3.4"
},
{
"binary_name": "bluez-tests",
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},
{
"binary_name": "libbluetooth3",
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}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-09T01:45:19.406932109Z",
"provider": "osv",
"upstream": [
"CVE-2021-43400"
],
"references": [
"https://ubuntu.com/security/CVE-2021-43400",
"https://ubuntu.com/security/notices/USN-5155-1",
"https://www.cve.org/CVERecord?id=CVE-2021-43400"
]
},
"related_cves": [
{
"value": "CVE-2021-43400",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 108242,
"published_at": "2021-11-04T23:15:00+00:00"
}