CVE intelligence and bounded remediation

CVE-2021-23842 — Communication to the AMC2 uses a state-of-the-art cryptographic algorithm for symmetric encryption called Blowfish

High CVSS 7.1

Communication to the AMC2 uses a state-of-the-art cryptographic algorithm for symmetric encryption called Blowfish. An attacker could retrieve the key from the firmware to decrypt network traffic between the AMC2 and the host system. Thus, an attacker can exploit this vulnerability to decrypt and modify network traffic, decrypt and further investigate the device\'s firmware file, and change the device configuration. The attacker needs to have access to the local network, typically even the same subnet.

Severity
High
CVSS
7.1 (3.1)
Published
2022-01-19
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-321, CWE-798

Affected products

  • bosch / amc2_firmware
  • bosch / access_management_system / 3.0
  • bosch / access_professional_edition
  • bosch / building_integration_system

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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