CVE-2021-28660

System crash via oversized wireless SSID

Published Mar 17, 2021 · Updated Aug 3, 2024

Out-of-bounds write in the Linux kernel through 5.11.6 allows attackers to crash systems via a crafted RTL8188EU scan request. The rtl8188eu rtw_wx_set_scan handler passes an unchecked SSID length to memcpy, allowing more than 32 bytes to overwrite the ssid array. The RTL8188EU staging driver must be present and its scan path must process the oversized SSID; the documented consequence is a system crash.

CVSS severity8.8
High
EPSS probability1.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the Linux kernel through 5.11.6 allows attackers to crash systems via a crafted RTL8188EU scan request. The rtl8188eu rtw_wx_set_scan handler passes an unchecked SSID length to memcpy, allowing more than 32 bytes to overwrite the ssid array. The RTL8188EU staging driver must be present and its scan path must process the oversized SSID; the documented consequence is a system crash.

The record

CVE
CVE-2021-28660
Published
Mar 17, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.3NIST NVDAV:A/AC:L/Au:N/C:C/I:C/A:C

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

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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