CVE-2020-25857: realtek rtl8195a_firmware Stack-based Buffer Overflow

Vulnerability summary

CVE-2020-25857 is a high (CVSS 7.5) Stack-based Buffer Overflow vulnerability in realtek rtl8195a_firmware. EPSS estimates a 1.23% chance of exploitation in the next 30 days, higher than 68.4% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 03-02-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.