MediumFix available
bluez-firmware — security advisory
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 does not properly handle the reception of a malformed LMP timing accuracy response followed by multiple reconnections to the link slave, allowing attackers to exhaust device BT resources and eventually trigger a crash via multiple attempts of sending a crafted LMP timing accuracy response followed by a sudden reconnection with a random BDAddress.
- Products
- bluez-firmware
- Affected versions
- 1.0-2, 1.0-3, 1.2-1, 1.2-2, 1.2-3, 1.2-4, 1.2-5, 1.2-6, 1.2-7, 1.2-7~bpo11+1, 1.2-8~bpo11+1
- Fixed versions
- 1.2-8
- CVEs
- CVE-2021-34147
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:34 UTC · Revision 1
Source evidence
The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 does not properly handle the reception of a malformed LMP timing accuracy response followed by multiple reconnections to the link slave, allowing attackers to exhaust device BT resources and eventually trigger a crash via multiple attempts of sending a crafted LMP timing accuracy response followed by a sudden reconnection with a random BDAddress.
osv:DEBIAN-CVE-2021-34147
bluez-firmware
Fixed versions: 1.2-8
bluez-firmware
Fixed versions: 1.2-8
bluez-firmware
Fixed versions: 1.2-8
Complete source record
{
"id": "875f426d20296874bb5b2895bfa62cd6b6c3b401204fec49cba30bfe71f55760",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-34147",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-34147",
"summary": "The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 does not properly handle the reception of a malformed LMP timing accuracy response followed by multiple reconnections to the link slave, allowing attackers to exhaust device BT resources and eventually trigger a crash via multiple attempts of sending a crafted LMP timing accuracy response followed by a sudden reconnection with a random BDAddress.",
"evidence": "osv:DEBIAN-CVE-2021-34147",
"products": [
{
"name": {
"value": "bluez-firmware",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.2-8",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "1.0-3",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-2",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-3",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-4",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-5",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-6",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-7",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-7~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "1.2-8~bpo11+1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "bluez-firmware",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.2-8",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "1.0-3",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-2",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-3",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-4",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-5",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-6",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-7",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-7~bpo11+1",
"evidence": "/affected/1/versions"
},
{
"value": "1.2-8~bpo11+1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "bluez-firmware",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.2-8",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "1.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.0-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-4",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-5",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-6",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-7",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-7~bpo11+1",
"evidence": "/affected/2/versions"
},
{
"value": "1.2-8~bpo11+1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-34147",
"aliases": [
"DEBIAN-CVE-2021-34147"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2-8"
}
]
}
],
"package": {
"name": "bluez-firmware",
"purl": "pkg:deb/debian/bluez-firmware?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.0-2",
"1.0-3",
"1.2-1",
"1.2-2",
"1.2-3",
"1.2-4",
"1.2-5",
"1.2-6",
"1.2-7",
"1.2-7~bpo11+1",
"1.2-8~bpo11+1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-34147.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2-8"
}
]
}
],
"package": {
"name": "bluez-firmware",
"purl": "pkg:deb/debian/bluez-firmware?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.0-2",
"1.0-3",
"1.2-1",
"1.2-2",
"1.2-3",
"1.2-4",
"1.2-5",
"1.2-6",
"1.2-7",
"1.2-7~bpo11+1",
"1.2-8~bpo11+1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-34147.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2-8"
}
]
}
],
"package": {
"name": "bluez-firmware",
"purl": "pkg:deb/debian/bluez-firmware?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.0-2",
"1.0-3",
"1.2-1",
"1.2-2",
"1.2-3",
"1.2-4",
"1.2-5",
"1.2-6",
"1.2-7",
"1.2-7~bpo11+1",
"1.2-8~bpo11+1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-34147.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:27.207817918Z",
"provider": "osv",
"upstream": [
"CVE-2021-34147"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-34147"
]
},
"related_cves": [
{
"value": "CVE-2021-34147",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 421560,
"published_at": "2021-09-07T07:15:07.373+00:00"
}