CVE-2020-27301Public exploit

Code execution via unchecked encrypted GTK length

Published Jun 4, 2021 · Updated Aug 4, 2024

A stack buffer overflow in Realtek RTL8710C and RTL8195A firmware allows attackers to execute code via a crafted WPA2 handshake. DecGTK passes an attacker-controlled 16-bit encrypted GTK length of up to 0xFFFF to AES_UnWRAP, which writes into the fixed 0x101-byte tmp2 stack buffer without a bounds check. Exploitation requires Wi-Fi reachability and knowledge of the network PSK; return-address overwrite grants control of the Wi-Fi module and can yield root access on the host OS.

CVSS severity8.0
High
EPSS probability1.99%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A stack buffer overflow in Realtek RTL8710C and RTL8195A firmware allows attackers to execute code via a crafted WPA2 handshake. DecGTK passes an attacker-controlled 16-bit encrypted GTK length of up to 0xFFFF to AES_UnWRAP, which writes into the fixed 0x101-byte tmp2 stack buffer without a bounds check. Exploitation requires Wi-Fi reachability and knowledge of the network PSK; return-address overwrite grants control of the Wi-Fi module and can yield root access on the host OS.

The record

CVE
CVE-2020-27301
Published
Jun 4, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1203
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 4, 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 vectoradjacent
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.0NIST NVDCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.7NIST NVDAV:A/AC:L/Au:S/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

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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