CVE-2021-43573Network attack vector

Memory corruption via malformed HT capability length

Published Nov 11, 2021 · Updated Aug 4, 2024

Buffer overflow in Realtek RTL8195AM firmware before 2.0.10 allows remote attackers to corrupt memory via crafted Wi-Fi frames. The client code trusts a malformed information-element length while parsing HT capability data in Beacon and Association response frames, causing a buffer overrun. Delivery requires a crafted frame to reach the Wi-Fi client; published sources do not establish whether the corruption causes a crash or code execution.

CVSS severity9.8
Critical
EPSS probability1.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Realtek RTL8195AM firmware before 2.0.10 allows remote attackers to corrupt memory via crafted Wi-Fi frames. The client code trusts a malformed information-element length while parsing HT capability data in Beacon and Association response frames, causing a buffer overrun. Delivery requires a crafted frame to reach the Wi-Fi client; published sources do not establish whether the corruption causes a crash or code execution.

The record

CVE
CVE-2021-43573
Published
Nov 11, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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