Security readout for executives and security teams
Plain-English summary
CVE-2019-8921 is a Bluetooth stack information leak in BlueZ bluetoothd through 5.48. A nearby attacker could cause the service to return heap memory beyond the intended buffer, potentially exposing sensitive data. The source bundle does not show CISA KEV listing or confirmed active exploitation.
Executive priority
Treat this as a targeted confidentiality risk, not an internet-scale emergency. Prioritize environments where Bluetooth is enabled near untrusted users, including laptops, embedded devices, and appliances. Patch through normal security maintenance unless business context increases adjacent-access risk.
Technical view
The flaw is in BlueZ SDP handling of SVC_ATTR_REQ in service_attr_req within sdpd-request.c. bluetoothd trusts continuation state data across requests instead of verifying it, allowing crafted CSTATE handling to leak arbitrary heap data. CVSS 3.1 is 6.5 with adjacent-network attack vector and high confidentiality impact.
Likely exposure
Exposure is most relevant to Linux, embedded, appliance, or storage environments using BlueZ bluetoothd through 5.48 with Bluetooth SDP reachable to adjacent attackers. The bundle lists affected vendor/product as n/a, so product mapping requires local inventory and vendor advisories.
Exploitation context
The attack vector is adjacent network, with no privileges or user interaction required. The provided sources describe malicious CSTATE handling and heap data leakage, but do not cite public active exploitation or CISA KEV inclusion.
Researcher notes
Evidence supports BlueZ through 5.48 and an SDP continuation-state validation flaw leading to heap disclosure. The source bundle does not provide complete affected product CPEs, fixed upstream version details, or proof of active exploitation, so validation should be inventory-driven and vendor-specific.
Mitigation direction
- Identify systems running BlueZ bluetoothd through version 5.48.
- Apply vendor-provided BlueZ security updates, including relevant Debian LTS updates where applicable.
- Review the NetApp advisory for product-specific exposure and remediation status.
- Follow operating-system vendor guidance before changing Bluetooth service availability.
Validation and detection
- Check installed BlueZ package versions against vendor-fixed releases.
- Confirm whether bluetoothd and SDP functionality are enabled on in-scope systems.
- Review asset inventory for Linux, embedded, and appliance systems with Bluetooth capability.
- Verify Debian systems received the DLA 3157-1 bluez security update where applicable.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-345: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-8921 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://ssd-disclosure.com/ssd-advisory-linux-bluez-information-leak-and-heap-overflow/CVE reference
- https://security.netapp.com/advisory/ntap-20211203-0002/CVE reference
- [debian-lts-announce] 20221024 [SECURITY] [DLA 3157-1] bluez security updateCVE reference · mailing-list
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Verification of Data Authenticity
Insufficient Verification of Data Authenticity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.