CVE Vulnerabilities

CVE-2021-20042

Unintended Proxy or Intermediary ('Confused Deputy')

Published: Dec 08, 2021 | Modified: Nov 21, 2024
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

An unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass firewall rules. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

Weakness

The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product’s control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor.

Affected Software

Name Vendor Start Version End Version
Sma_200_firmware Sonicwall 9.0.0.11-31sv (including) 9.0.0.11-31sv (including)
Sma_200_firmware Sonicwall 10.2.0.8-37sv (including) 10.2.0.8-37sv (including)
Sma_200_firmware Sonicwall 10.2.1.1-19sv (including) 10.2.1.1-19sv (including)

Extended Description

If an attacker cannot directly contact a target, but the product has access to the target, then the attacker can send a request to the product and have it be forwarded to the target. The request would appear to be coming from the product’s system, not the attacker’s system. As a result, the attacker can bypass access controls (such as firewalls) or hide the source of malicious requests, since the requests would not be coming directly from the attacker. Since proxy functionality and message-forwarding often serve a legitimate purpose, this issue only becomes a vulnerability when:

Potential Mitigations

References