CVE-2020-3702

What it actually does

Crafted and timed Wi-Fi traffic triggers internal errors in the WLAN device leading to improper layer 2 encryption and consequent over-the-air information disclosure for a discrete set of traffic.

Why it matters to the business

Attackers within Wi-Fi range can intercept sensitive data on affected Qualcomm-based devices, IoT systems, and wireless infrastructure, increasing breach risk across mobile, automotive, and networking deployments that have remained unpatched for years.

How an attack unfolds

An attacker within radio range sends specifically timed and handcrafted 802.11 frames targeting vulnerable Qualcomm WLAN chips; the resulting internal errors disable proper encryption for selected traffic, allowing passive capture of plaintext data over the air.

How to fix it

Apply the latest firmware updates from Qualcomm for all listed chipsets (APQ8053, IPQ4019, IPQ8064, MSM8909W, MSM8996AU, QCA9531, QCN5502, QCS405, SDX20, SM6150, SM7150) and downstream vendors including Debian Linux and Arista access points; replace end-of-life hardware that lacks patches.

How to confirm the fix worked

Compare running firmware versions against current Qualcomm and vendor security advisories; perform wireless traffic analysis to confirm encryption behavior matches patched expectations.

Typical attack path

1. Position within range of the target wireless network containing vulnerable Qualcomm chipset
2. Transmit crafted and precisely timed 802.11 management or data frames
3. Induce internal error state that bypasses layer-2 encryption
4. Capture and decrypt the resulting improperly protected frames

How to detect it

Inspect wireless packet captures and device logs for repeated malformed or timed 802.11 frames coinciding with encryption anomalies; correlate with known affected chipset MAC OUIs.

What your security team should do

• Inventory all devices using the listed Qualcomm chipsets and schedule immediate firmware updates
• Isolate legacy or unpatchable wireless devices on segmented networks
• Review wireless encryption configurations and enable additional protections such as WPA3 where supported