SonicWall Issues Patches for a New Critical Flaw in SMA 100 Series Devices

Network security company SonicWall has addressed a critical
security vulnerability affecting its Secure Mobile Access (SMA) 100
series appliances that can permit remote, unauthenticated attackers
to gain administrator access on targeted devices remotely.

Tracked as CVE-2021-20034^[1], the arbitrary file
deletion flaw is rated 9.1 out of a maximum of 10 on the CVSS
scoring system, and could allow an adversary to bypass path
traversal checks and delete any file, causing the devices to reboot
to factory default settings.

“The vulnerability is due to an improper limitation of a file
path to a restricted directory potentially leading to arbitrary
file deletion as ‘nobody,'” the San Jose-based firm noted^[2]
in an advisory published Thursday. “There is no evidence that this
vulnerability is being exploited in the wild.”

SonicWall credited Wenxu Yin of Alpha Lab, Qihoo 360, with
reporting the security shortcoming, which impacts SMA 100 Series —
SMA 200, SMA 210, SMA 400, SMA 410, and SMA 500v — running the
following versions:

• 9.0.0.10-28sv and earlier
• 10.2.0.7-34sv and earlier
• 10.2.1.0-17sv and earlier

Given that there are no workarounds to remediate the attack
vector and SonicWall devices have become a lucrative target^[3]
for threat actors to deploy ransomware in recent months, customers
are advised to implement applicable patches as soon as possible to
mitigate any potential exploitation risk.