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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-12503
StatePUBLISHED
AssignerNCSC.ch
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-24 15:17:10 UTC
Updated2026-07-24 15:17:10 UTC
DescriptionImproper 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`.

Risk And Classification

Primary CVSS: v4.0 9.2 CRITICAL from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.001360000 probability, percentile 0.034250000 (date 2026-07-25)

Problem Types: CWE-59 | CWE-59 CWE-59 Improper link resolution before file access ('link following')

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.2CRITICALCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:H/SA:N/E:X/C...
4.0CNACVSS9.2CRITICALCVSS: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 v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
High
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
High
Sub Availability
None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Loytec LIP-ME20xC affected 8.4.16 custom Not specified
CNA Loytec L-INX affected 8.4.16 custom Not specified
CNA Loytec L-GATE affected 8.4.16 custom Not specified
CNA Loytec L-ROC affected 8.4.16 custom Not specified
CNA Loytec L-IOB affected 8.4.16 custom Not specified
CNA Loytec L-DALI affected 8.4.16 custom Not specified
CNA Loytec L-VIS affected 8.4.16 custom Not specified
CNA Loytec L-PAD affected 8.4.16 custom Not specified

References

ReferenceSourceLinkTags
www.loytec.com/support/product-security/advisories/8520-dibt-cve-20260526-00... [email protected] www.loytec.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Daniel Hulliger, armasuisse CYD Campus (en)

CNA: Damian Pfammatter, armasuisse CYD Campus (en)

Additional Advisory Data

Solutions

CNA: Upgrade to firmware 8.4.18.

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