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CVE-2017-7902: Rockwellautomation 1763 L16awa Series A: Reusing a Nonce, Key Pair in Encryption

CVE-2017-7902 is rated critical with a CVSS v3.0 base score of 9.8 and affects Rockwellautomation 1763 L16awa Series A, along with 10 other products in NVD’s configuration data. 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

A "Reusing a Nonce, Key Pair in Encryption" issue was discovered in Rockwell Automation Allen-Bradley MicroLogix 1100 programmable-logic controllers 1763-L16AWA, Series A and B, Version 16.00 and prior versions; 1763-L16BBB, Series A and B, Version 16.00 and prior versions; 1763-L16BWA, Series A and B, Version 16.00 and prior versions; and 1763-L16DWD, Series A and B, Version 16.00 and prior versions and Allen-Bradley MicroLogix 1400 programmable logic controllers 1766-L32AWA, Series A and B, Version 16.00 and prior versions; 1766-L32BWA, Series A and B, Version 16.00 and prior versions; 1766-L32BWAA, Series A and B, Version 16.00 and prior versions; 1766-L32BXB, Series A and B, Version 16.00 and prior versions; 1766-L32BXBA, Series A and B, Version 16.00 and prior versions; and 1766-L32AWAA, Series A and B, Version 16.00 and prior versions. The affected product reuses nonces, which may allow an attacker to capture and replay a valid request until the nonce is changed.

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-323: Reusing a Nonce, Key Pair in Encryption

Nonces should be used for the present occasion and only once.

CWE-330: Use of Insufficiently Random Values

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected products

  • Rockwellautomation 1763 L16awa Series A: up to and including 16.000
  • Rockwellautomation 1763 L16bbb Series A: up to and including 16.000
  • Rockwellautomation 1763 L16bwa Series A: up to and including 16.000
  • Rockwellautomation 1763 L16dwd Series A: up to and including 16.000
  • Rockwellautomation 1766 L32awa Series A: up to and including 16.000
  • Rockwellautomation 1766 L32awaa Series A: up to and including 16.000
  • Rockwellautomation 1766 L32bwa Series A: up to and including 16.000
  • Rockwellautomation 1766 L32bwaa Series A: up to and including 16.000
  • Rockwellautomation 1766 L32bxb Series A: up to and including 16.000
  • Rockwellautomation 1766 L32bxba Series A: up to and including 16.000
  • Rockwellautomation 1763 L16awa Series B: up to and including 16.000
  • Rockwellautomation 1763 L16bbb Series B: up to and including 16.000
  • Rockwellautomation 1763 L16bwa Series B: up to and including 16.000
  • Rockwellautomation 1763 L16dwd Series B: up to and including 16.000
  • Rockwellautomation 1766 L32awa Series B: up to and including 16.000

References