CVE-2020-25854

Remote code execution via unchecked WPA2 key length

Published Feb 3, 2021 · Updated Aug 4, 2024

Stack buffer overflow in RTL8195A Firmware before 2.08 allows remote attackers to execute code or crash a Wi-Fi client. DecWPA2KeyData passes an attacker-controlled size to rt_arc4_crypt_veneer() or _AES_UnWRAP_veneer() without validating it, overflowing a stack buffer. Exploitation requires knowledge of the network PSK and an impersonated access point that injects crafted key data during the WPA2 handshake.

CVSS severity8.1
High
EPSS probability2.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in RTL8195A Firmware before 2.08 allows remote attackers to execute code or crash a Wi-Fi client. DecWPA2KeyData passes an attacker-controlled size to rt_arc4_crypt_veneer() or _AES_UnWRAP_veneer() without validating it, overflowing a stack buffer. Exploitation requires knowledge of the network PSK and an impersonated access point that injects crafted key data during the WPA2 handshake.

The record

CVE
CVE-2020-25854
Published
Feb 3, 2021
Updated
Aug 4, 2024
Vendor
Realtek Semiconductor Corp.
Product
RTL8195A Firmware
Classifications
CWE-787, CWE-121, T1203
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Versions before 2020-04-21 (up to and excluding 2.08)

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Realtek Semiconductor Corp. · RTL8195A Firmwareversion=Versions before 2020-04-21 (up to and excluding 2.08)

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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
CWE-121Stack-based Buffer Overflow
T1203Exploitation for Client Execution

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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