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CVE-2017-9855: This system uses predictable codes, and a single Grid Guard code can be used on any SMA inverter.

CVE-2017-9855 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 39 affected products, including Sma Sunny Boy 3600 Firmware. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An issue was discovered in SMA Solar Technology products. A secondary authentication system is available for Installers called the Grid Guard system. This system uses predictable codes, and a single Grid Guard code can be used on any SMA inverter. Any such code, when combined with the installer account, allows changing very sensitive parameters. NOTE: the vendor reports that Grid Guard is not an authentication feature; it is only a tracing feature. Also, only Sunny Boy TLST-21 and TL-21 and Sunny Tripower TL-10 and TL-30 could potentially be affected

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-863: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Affected products

  • Sma Sunny Boy 3600 Firmware: all versions listed by NVD
  • Sma Sunny Boy 5000 Firmware: all versions listed by NVD
  • Sma Sunny Tripower Core1 Firmware: all versions listed by NVD
  • Sma Sunny Tripower 15000tl Firmware: all versions listed by NVD
  • Sma Sunny Tripower 20000tl Firmware: all versions listed by NVD
  • Sma Sunny Tripower 25000tl Firmware: all versions listed by NVD
  • Sma Sunny Tripower 5000tl Firmware: all versions listed by NVD
  • Sma Sunny Tripower 12000tl Firmware: all versions listed by NVD
  • Sma Sunny Tripower 60 Firmware: all versions listed by NVD
  • Sma Sunny Boy 3000tl Firmware: all versions listed by NVD
  • Sma Sunny Boy 3600tl Firmware: all versions listed by NVD
  • Sma Sunny Boy 4000tl Firmware: all versions listed by NVD
  • Sma Sunny Boy 5000tl Firmware: all versions listed by NVD
  • Sma Sunny Boy 1.5 Firmware: all versions listed by NVD
  • Sma Sunny Boy 2.5 Firmware: all versions listed by NVD

References