CVE intelligence and bounded remediation

CVE-2020-25853 — Realtek Rtl8195A Firmware security vulnerability

High CVSS 7.5

The function CheckMic() 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 internal function, _rt_md5_hmac_veneer() or _rt_hmac_sha1_veneer(), resulting in a stack buffer over-read 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.

Severity
High
CVSS
7.5 (3.1)
Published
2021-02-03
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-126, CWE-125

Affected products

  • realtek / rtl8195a_firmware

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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