CVE-2020-25857Network attack vector

Service interruption via unchecked WPA2 packet copy

Published Feb 3, 2021 · Updated Aug 4, 2024

Stack buffer overflow in Realtek RTL8195A Wi-Fi Module before 2.08 allows remote attackers to interrupt service via a crafted WPA2 packet. ClientEAPOLKeyRecvd() passes an unchecked packet-derived size to rtl_memcpy(), overflowing a stack buffer during handshake processing. An attacker must impersonate an access point and inject the packet into a client handshake; the network PSK is not required, and the reported consequence is service interruption.

CVSS severity7.5
High
EPSS probability1.23%
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 Realtek RTL8195A Wi-Fi Module before 2.08 allows remote attackers to interrupt service via a crafted WPA2 packet. ClientEAPOLKeyRecvd() passes an unchecked packet-derived size to rtl_memcpy(), overflowing a stack buffer during handshake processing. An attacker must impersonate an access point and inject the packet into a client handshake; the network PSK is not required, and the reported consequence is service interruption.

The record

CVE
CVE-2020-25857
Published
Feb 3, 2021
Updated
Aug 4, 2024
Vendor
Realtek Semiconductor Corp.
Product
RTL8195A Wi-Fi Module
Classifications
CWE-787, CWE-121, T1499.004
Attack vector
network
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 vectornetwork
Required privilegesunauthenticated

What is affected?

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

Published CVSS scores

5.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

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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