How severe is CVE-2020-25857?

CVE-2020-25857 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-25857 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-25857?

CVE-2020-25857 affects Realtek Rtl8195a Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-25857?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-25857 published?

CVE-2020-25857 was published on 2021-02-03 and last updated on 2026-06-17.

CVE-2020-25857

CVE-2020-25857 is a high-severity vulnerability in Realtek Rtl8195a Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Realtek Rtl8195a Firmware
Published: 2021-02-03
Last modified: 2026-06-17

Description

The function ClientEAPOLKeyRecvd() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and excluding 2.08) does not validate the size parameter for an rtl_memcpy() operation, resulting in a stack buffer overflow which can be exploited for denial of service. An attacker can impersonate an Access Point and attack a vulnerable Wi-Fi client, by injecting a crafted packet into the WPA2 handshake. The attacker does not need to know the network's PSK.

Frequently asked questions

What is CVE-2020-25857?: The function ClientEAPOLKeyRecvd() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and excluding 2.08) does not validate the size parameter for an rtl_memcpy() operation, resulting in a stack buffer overflow which can be exploited for denial of service. An attacker can impersonate an Access Point and attack a vulnerable Wi-Fi client, by injecting a crafted packet into the WPA2 handshake. The attacker does not need to know the network's PSK.
How severe is CVE-2020-25857?: CVE-2020-25857 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-25857 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-25857?: CVE-2020-25857 affects Realtek Rtl8195a Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-25857?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-25857 published?: CVE-2020-25857 was published on 2021-02-03 and last updated on 2026-06-17.

References

https://www.vdoo.com/blog/realtek-rtl8195a-vulnerabilities-discovered/

Affected products (1)

cpe:2.3:o:realtek:rtl8195a_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Realtek Rtl8195a Firmware

CVE-2020-25856 — High (CVSS 8.1): The function DecWPA2KeyData() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and…
CVE-2020-25855 — High (CVSS 8.1): The function AES_UnWRAP() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and…
CVE-2020-25854 — High (CVSS 8.1): The function DecWPA2KeyData() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and…
CVE-2020-27302 — High (CVSS 8.0): A stack buffer overflow in Realtek RTL8710 (and other Ameba-based devices) can lead to remote code execution via the…
CVE-2020-27301 — High (CVSS 8.0): A stack buffer overflow in Realtek RTL8710 (and other Ameba-based devices) can lead to remote code execution via the…
CVE-2020-25853 — High (CVSS 7.5): The function CheckMic() in the Realtek RTL8195A Wi-Fi Module prior to versions released in April 2020 (up to and…

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