cbcvebase.
CVE-2016-8380
published 2018-04-05

CVE-2016-8380: The web server in Phoenix Contact ILC PLCs allows access to read and write PLC variables without authentication.

PriorityP262high7.3CVSS 3.0
AVNACLPRNUINSUCLILAL
EXPLOIT
EPSS
11.20%
95.4th percentile
The web server in Phoenix Contact ILC PLCs allows access to read and write PLC variables without authentication.

Affected

1 ranges
VendorProductVersion rangeFixed in
phoenix_contactphoenix_contact_ilc_plcs

Detection & IOCsextracted from sources · hover to see the quote

urlhttp://<host>/cgi-bin/ILRReadValues.exe
urlhttp://<host>/cgi-bin/writeVal.exe?<tag>+<value>
path/cgi-bin/ILRReadValues.exe
path/cgi-bin/writeVal.exe
filename<ProjectName>.tcr
  • Detect unauthenticated HTTP GET requests to /cgi-bin/ILRReadValues.exe on Phoenix Contact ILC PLC web servers — this endpoint exposes all PLC tag values without authentication.
  • Detect unauthenticated HTTP GET requests to /cgi-bin/writeVal.exe on Phoenix Contact ILC PLC web servers — this endpoint allows writing arbitrary PLC variable values without authentication.
  • Detect HTTP requests fetching *.tcr files from the PLC root — this file enumerates all PLC tag names and is a precursor step in exploitation.
  • Monitor for HTTP requests to the PLC root page (/) that parse the 'ProjectName' VALUE field — this is the reconnaissance step used to discover the project name before fetching the .tcr tag list.
  • The web server allows access to read and write PLC variables without authentication — alert on any access to ILRReadValues.exe or writeVal.exe from untrusted network segments.
  • ·The authentication bypass (CVE-2016-8371) means even password-protected HMI pages can be bypassed — do not rely on the WebVisit password macro as a security control.
  • ·The WebVisit password macro can be configured to store and transfer passwords in cleartext (CVE-2016-8366) — inspect configurations for plaintext password storage.
  • ·All ILC 1xx PLC firmware versions are affected; only ILC 1x1 PLCs with Firmware 4.42 or later offer HTTPS, which partially mitigates exposure.

CVSS provenance

nvdv3.07.3HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
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