CVE-2021-35395 Information

Description

Realtek Jungle SDK version v2.x up to v3.4.14B provides an HTTP web server exposing a management interface that can be used to configure the access point. Two versions of this management interface exists: one based on Go-Ahead named webs and another based on Boa named boa. Both of them are affected by these vulnerabilities. Specifically these binaries are vulnerable to the following issues: - stack buffer overflow in formRebootCheck due to unsafe copy of submit-url parameter - stack buffer overflow in formWsc due to unsafe copy of submit-url parameter - stack buffer overflow in formWlanMultipleAP due to unsafe copy of submit-url parameter - stack buffer overflow in formWlSiteSurvey due to unsafe copy of ifname parameter - stack buffer overflow in formStaticDHCP due to unsafe copy of hostname parameter - stack buffer overflow in formWsc due to unsafe copy of ‘peerPin’ parameter - arbitrary command execution in formSysCmd via the sysCmd parameter - arbitrary command injection in formWsc via the ‘peerPin’ parameter Exploitability of identified issues will differ based on what the end vendor/manufacturer did with the Realtek SDK webserver. Some vendors use it as-is others add their own authentication implementation some kept all the features from the server some remove some of them some inserted their own set of features. However given that Realtek SDK implementation is full of insecure calls and that developers tends to re-use those examples in their custom code any binary based on Realtek SDK webserver will probably contains its own set of issues on top of the Realtek ones (if kept). Successful exploitation of these issues allows remote attackers to gain arbitrary code execution on the device.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf Realtek Jungle SDK version v2.x up to v3.4.14B provides an HTTP web server exposing a management interface that can be used to configure the access point. Two versions of this management interface exists: one based on Go-Ahead named webs and another based on Boa named boa. Both of them are affected by these vulnerabilities. Specifically these binaries are vulnerable to the following issues:

stack buffer overflow in formRebootCheck due to unsafe copy of submit-url parameter

stack buffer overflow in formWsc due to unsafe copy of submit-url parameter

stack buffer overflow in formWlanMultipleAP due to unsafe copy of submit-url parameter

stack buffer overflow in formWlSiteSurvey due to unsafe copy of ifname parameter

stack buffer overflow in formStaticDHCP due to unsafe copy of hostname parameter

stack buffer overflow in formWsc due to unsafe copy of ‘peerPin’ parameter

arbitrary command execution in formSysCmd via the sysCmd parameter

arbitrary command injection in formWsc via the ‘peerPin’ parameter Exploitability of identified issues will differ based on what the end vendor/manufacturer did with the Realtek SDK webserver. Some vendors use it as-is others add their own authentication implementation some kept all the features from the server some remove some of them some inserted their own set of features. However given that Realtek SDK implementation is full of insecure calls and that developers tends to re-use those examples in their custom code any binary based on Realtek SDK webserver will probably contains its own set of issues on top of the Realtek ones (if kept). Successful exploitation of these issues allows remote attackers to gain arbitrary code execution on the device.

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8