Vendor: SonicWall
Vendor URL: https://www.sonicwall.com/
Versions affected: 10.2.0.8-37sv, 10.2.1.1-19sv
Systems Affected: SMA 100 Series (SMA 200, 210, 400, 410, 500v)
Author: Richard Warren <richard.warren[at]nccgroup[dot]trust>
Advisory URL: https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026
CVE Identifier: CVE-2021-20043
Risk: CVSS 8.8 (High)

Summary

SonicWall SMA 100 Series appliances running firmware versions 10.2.0.8-37sv, 10.2.1.1-19sv and below suffer from a heap-based buffer overflow vulnerability in the sonicfiles RAC_GET_BOOKMARKS_HTML5 API. This vulnerability arises due to the unchecked use of the strcat function on a fixed size buffer, when displaying user bookmarks. This vulnerability requires authentication as a low privileged user.

Impact

An authenticated low-privileged user could exploit this vulnerability to achieve code execution as the nobody user.

Recommendation

Upgrade to SMA version 10.2.0.9-41sv, 10.2.1.3-27sv or above.

Vendor Communication

2021-10-29 - Vulnerability reported to SonicWall PSIRT.
2021-11-02 - Acknowledgement from SonicWall PSIRT.
2021-12-01 - SonicWall request that NCC Group withhold technical details until 2022-01-11, releasing high-level advisories on 2021-12-09.
2021-12-03 - NCC Group agrees to suggested disclosure timeline.
2021-12-07 - Patch released and SonicWall publish KB article and security advisory.
2021-12-09 - NCC Group advisory released.

Thanks to

Jennifer Fernick and Aaron Haymore from NCC Group for their assistance with disclosure.

About NCC Group

NCC Group is a global expert in cybersecurity and risk mitigation, working with businesses to protect their brand, value and reputation against the ever-evolving threat landscape. With our knowledge, experience and global footprint, we are best placed to help businesses identify, assess, mitigate & respond to the risks they face. We are passionate about making the Internet safer and revolutionizing the way in which organizations think about cybersecurity.

Published Date: 2021-12-09

Written By: Richard Warren

Published