External risk intelligence

SonicWall Email Security Arbitrary File Upload Vulnerability

CVE advisoryKnown Exploit

CVE-2021-20022

An authenticated attacker can upload arbitrary files to SonicWall Email Security systems, potentially leading to unauthorized access or data modification. This poses a risk to email infrastructure and data confidentiality. Organizations should identify affected assets and apply vendor fixes.

4Halo Surface Signal

Unrestricted File Upload

Sonicwall Email Security

before 10.0.9.6103before 10.0.9.6105

External exposure likelihood

Halo Surface Signal score for CVE-2021-20022

The product is an email security appliance or gateway. These devices are designed to reside at the network perimeter to filter incoming traffic and are commonly exposed to the public internet to receive mail and provide administrative access.

Horizon Alert

Summary of the vulnerability and why it matters

SonicWall Email Security contains a vulnerability that allows an authenticated attacker to upload arbitrary files to the system. This could lead to unauthorized access or modification of data. The flaw exists within the file upload functionality of the product.

  • Vulnerable email security component
  • Unrestricted file upload capability
  • Potential data compromise and unauthorized access

Attack Path

How an attacker could exploit the issue

This vulnerability allows an authenticated attacker to upload arbitrary files to a SonicWall Email Security system. Successful exploitation could lead to the compromise of system integrity and confidentiality. The attack leverages an unrestricted file upload capability, potentially enabling an attacker to execute malicious code or overwrite critical system files. This poses a significant risk to the affected organization's email infrastructure and data.

  • Authenticated access to the system.
  • Attacker uploads a malicious file.
  • Arbitrary file upload achieved.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow a sophisticated attacker to upload arbitrary files to a targeted system. This could lead to unauthorized access, modification of data, or disruption of services. Due to the potential for severe impact, organizations should prioritize addressing this vulnerability.

  • Likely attacker skill level: High
  • Required access or conditions: Authenticated access
  • Business risk or urgency: High

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability allows an authenticated attacker to upload arbitrary files, potentially impacting system integrity and confidentiality. The organization should take immediate action to identify and mitigate risks associated with this vulnerability.

  • Find affected SonicWall Email Security assets.
  • Restrict access to mitigate exposure.
  • Apply vendor fixes and verify.
  • Monitor for related activity.

Frequently asked questions

What is SonicWall Email Security?

SonicWall Email Security is a product designed to protect email systems from threats. It acts as a gateway, filtering incoming emails to prevent malware, spam, and other malicious content from reaching users. This helps organizations maintain the security and integrity of their email infrastructure.

What kind of weakness does CVE-2021-20022 describe?

CVE-2021-20022 describes a CWE-434 weakness, also known as 'Unrestricted Upload of File with Dangerous Type'. This means the software allows users to upload files without proper checks on the file type, potentially enabling the upload of malicious files like executables.

What must an attacker do to exploit this SonicWall flaw?

An attacker must first be authenticated to the SonicWall Email Security system to exploit this vulnerability. The vulnerability is triggered when the attacker uploads an arbitrary file, which is allowed by the system without sufficient type validation.

How exposed is SonicWall Email Security to external threats?

SonicWall Email Security is classified as having external exposure. This means it is likely to be internet-facing, designed to process incoming traffic from the public internet to filter emails. Such devices are generally more accessible to potential attackers.

What is the first step for running SonicWall Email Security?

Organizations running SonicWall Email Security should first identify all instances of the affected product within their environment. Following identification, applying the vendor's provided fixes or updates is the critical next step to mitigate the vulnerability.

References