CVE-2021-3329— DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer
Quick assessment
Affected
zephyrproject-rtos zephyr
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Zephyr是Zephyr Project开源的一个可扩展的实时操作系统 (RTOS)。 Zephyr v2.4.0版本存在安全漏洞，该漏洞源于在 hci 主机堆栈初始化期间，无效的 ACL_MTU 数据包没有得到正确处理，攻击者利用该漏洞可以通过蓝牙控制器发送恶意 ACL_MTU 数据包导致 HCI主机层崩溃。
Possible ATT&CK Techniques 1 AI
T1211 · Exploitation for Stealth
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2021-3329
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer
Source: CVE Program / CVE List V5
Vulnerability Description
Lack of proper validation in HCI Host stack initialization can cause a crash of the bluetooth stack
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
对异常条件检查或处理不恰当
Source: CVE Program / CVE List V5
Vulnerability Title
Zephyr 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Zephyr是Zephyr Project开源的一个可扩展的实时操作系统 (RTOS)。 Zephyr v2.4.0版本存在安全漏洞，该漏洞源于在 hci 主机堆栈初始化期间，无效的 ACL_MTU 数据包没有得到正确处理，攻击者利用该漏洞可以通过蓝牙控制器发送恶意 ACL_MTU 数据包导致 HCI主机层崩溃。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| zephyrproject-rtos | zephyr | unspecified ~ v2.4 | - |
|
II. Public POCs for CVE-2021-3329
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2021-3329
请登录查看更多情报信息。
Other References for CVE-2021-3329 (1)
IV. Related Vulnerabilities
Same product: zephyr
-
CVE-2026-17053
SMBus callback-removal syscalls accept an unvalidated user p -
CVE-2026-18747
Integer underflow of net_buf length in the MCUmgr serial (SM -
CVE-2026-18746
NULL pointer dereference in Zephyr LwM2M client when the CoA -
CVE-2026-18417
Wild pointer dereference in Zephyr BSD sockets when a TCP li -
CVE-2026-18416
Out-of-bounds read in CoAP well-known-core Uri-Query href ma
Same vendor: zephyrproject-rtos
-
CVE-2026-13351
net: Maliciously fragmented IPv6 packets can prevent receivi -
CVE-2026-5068
bt: l2cap le coc: remote oob write via seg counter stored in -
CVE-2026-5067
Out-of-bounds read/write in HTTP WebSocket upgrade via non-n -
CVE-2026-5066
net: sockets: tls: Potential out-of-bounds write/read in soc -
CVE-2026-5589
Out-of-bounds write caused by an integer underflow in the Bl
Same weakness: CWE-703
-
CVE-2026-61822
pg_partman disable maintenance for all partition sets -
CVE-2026-92790
Higress before 2.2.4 Rate Limit Bypass via Malformed Cookie -
CVE-2026-20329
Cisco Secure Adaptive Security Appliance Software, Secure Fi -
CVE-2026-80135
Dell Secure Connect Gateway 异常处理不当漏洞 -
CVE-2026-57445
Gardens v2: Approve-side dispute resolution drains active st
V. Comments for CVE-2021-3329
No comments yet