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CISA tags SonicWall VPN flaw as actively exploited in attacks

BleepingComputer
·
Sergiu Gatlan
·
Published Apr 17, 2025
·
Updated

On Wednesday, CISA warned federal agencies to secure their SonicWall Secure Mobile Access (SMA) 100 series appliances against attacks exploiting a high-severity remote code execution vulnerability. Tracked as CVE-2021-20035, this security flaw impacts SMA 200, SMA 210, SMA 400, SMA 410, and SMA 500v (ESX, KVM, AWS, Azure) devices. Successful exploitation can allow remote threat actors with low privileges to execute arbitrary code in low-complexity attacks. "Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user, which could potentially lead to code execution," SonicWall explains in an advisory updated this week. SonicWall patched this vulnerability almost four years ago, in September 2021, when the company said it could only be exploited to take down vulnerable appliances in denial-of-service (DoS) attacks. However, on Monday, it updated the CVE-2021-20035 security advisory to flag it as exploited in attacks, upgrade the CVSS severity score from medium to high, and expand the impact to include code execution. "This vulnerability is believed to be actively exploited in the wild. As a precautionary measure, SonicWall PSIRT has updated the summary and revised the CVSS score to 7.2," SonicWall said. Yesterday, CISA confirmed the vulnerability is now being abused in the wild by adding it to the Known Exploited Vulnerabilities catalog, which lists security flaws flagged b...

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Affected Software

14 affected components
SonicWall SMA 200
SonicWall Sma 210
SonicWall Sma 400
SonicWall Sma 410
SonicWall Sma 500v=ESX
SonicWall Sma 500v=KVM
SonicWall Sma 500v=AWS
SonicWall Sma 500v=Azure
SonicWall Secure Mobile Access=100
SonicWall Secure Mobile Access=200
SonicWall Secure Mobile Access=210
SonicWall Secure Mobile Access=400
SonicWall Secure Mobile Access=410
SonicWall Secure Mobile Access=500v
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Frequently Asked Questions

1

What is the main topic of this article?

The article discusses a high-severity remote code execution vulnerability in SonicWall VPN appliances that is actively being exploited.

2

What is the severity level of the SonicWall VPN vulnerability?

The vulnerability is categorized as high severity due to the potential for remote code execution.

3

What specific products are affected by this SonicWall security flaw?

The affected products include SonicWall SMA 200, SMA 210, SMA 400, SMA 410, and SMA 500v series appliances.

4

What actions is CISA urging federal agencies to take regarding the SonicWall flaw?

CISA is urging federal agencies to secure their SonicWall Secure Mobile Access appliances to prevent exploitation.

5

What is the CVE identifier for the SonicWall VPN vulnerability?

The vulnerability is tracked as CVE-2021-20035.

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