Realtek RTL8195A prior 2.08 WPA2 Handshake CheckMic size stack-based overflow

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CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

A vulnerability, which was classified as critical, was found in Realtek RTL8195A. This affects the function CheckMic of the component WPA2 Handshake Handler. The manipulation of the argument size with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-121. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was disclosed 02/04/2021. It is possible to read the advisory at vdoo.com. This vulnerability is uniquely identified as CVE-2020-25853 since 09/23/2020. The exploitability is told to be easy. Access to the local network is required for this attack. The requirement for exploitation is a authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 2.08 eliminates this vulnerability.

Productinfoedit

Vendor

Realtek

Name

RTL8195A

CPE 2.3infoedit

🔒

CPE 2.2infoedit

🔒

CVSSv3infoedit

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2infoedit

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VulDB Base Score: 🔒
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VulDB Reliability: 🔍

Exploitinginfoedit

Class: Memory corruption
CWE: CWE-121
ATT&CK: Unknown

Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfoedit

Threat: 🔍
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Countermeasuresinfoedit

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: RTL8195A 2.08

Timelineinfoedit

09/23/2020 CVE assigned
02/04/2021 +134 days Advisory disclosed
02/04/2021 +0 days VulDB entry created
02/23/2021 +19 days VulDB last update

Sourcesinfoedit

Advisory: vdoo.com
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2020-25853 (🔒)

Entryinfoedit

Created: 02/04/2021 10:16 AM
Updated: 02/23/2021 12:31 PM
Changes: (6) source_cve_assigned source_cve_nvd_summary advisory_confirm_url vulnerability_cvss2_vuldb_tempscore vulnerability_cvss3_vuldb_tempscore vulnerability_cvss3_meta_tempscore
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