CVE-2026-12503 PUBLISHED

Loytec LINX firmware: Improper Link Resolution in /usr/bin/larm_starter

Assigner: NCSC.ch
Reserved: 17.06.2026 Published: 24.07.2026 Updated: 24.07.2026

Improper Link Resolution (CWE-59) in /usr/bin/larm_starter in Loytec L-INX, L-GATE, L-ROC, L-IOB, L-DALI, L-VIS and L-PAD through 8.4.16 on LINX-A64 allows an authenticated larmapp attacker to make /etc/passwd writable by the larmapp group (leading to root privilege escalation) via a symlink attack on /etc/lighttpd/ssl/server.pem.

Metrics

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:H/SA:N
CVSS Score: 9.2

Product Status

Vendor Loytec
Product LIP-ME20xC
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-INX
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-GATE
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-ROC
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-IOB
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-DALI
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-VIS
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)
Vendor Loytec
Product L-PAD
Versions Default: unaffected
  • affected from 0 to 8.4.16 (incl.)

Solutions

Upgrade to firmware 8.4.18.

Credits

  • Daniel Hulliger, armasuisse CYD Campus finder
  • Damian Pfammatter, armasuisse CYD Campus finder

References

Problem Types

  • CWE-59 Improper link resolution before file access ('link following') CWE

Impacts

  • CAPEC-122 Privilege Abuse
  • CAPEC-233 Privilege Escalation