Vulnerability-Lookup

GHSA-4P7F-6RPF-28MQ

Vulnerability from github – Published: 2026-07-24 15:33 – Updated: 2026-07-24 15:33

Details

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.

Severity

9.2 (Critical)


                  
                    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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-12503"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-59"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-24T15:17:10Z",
    "severity": "CRITICAL"
  },
  "details": "Improper Link Resolution (CWE-59)\u00a0in `/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`.",
  "id": "GHSA-4p7f-6rpf-28mq",
  "modified": "2026-07-24T15:33:01Z",
  "published": "2026-07-24T15:33:01Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12503"
    },
    {
      "type": "WEB",
      "url": "https://www.loytec.com/support/product-security/advisories/8520-dibt-cve-20260526-0002-symlink-following-in-chown-chmod-critical"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-12503 (GCVE-0-2026-12503)

Vulnerability from cvelistv5 – Published: 2026-07-24 13:57 – Updated: 2026-07-24 14:57

Title

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

Summary

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`.

Severity

9.2 (Critical)


                        
                          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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-24 14:57 UTC

CWE

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

Assigner

NCSC.ch mitre root Scorecard

References

1 reference

URL	Tags
https://www.loytec.com/support/product-security/a…	vendor-advisory

Impacted products

8 products

Vendor	Product	Version
Loytec	LIP-ME20xC	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-INX	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-GATE	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-ROC	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-IOB	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-DALI	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-VIS	Affected: 0 , ≤ 8.4.16 (custom)
Loytec	L-PAD	Affected: 0 , ≤ 8.4.16 (custom)

Credits

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

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-12503",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-24T14:57:37.633031Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-24T14:57:47.202Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "LIP-ME20xC",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-INX",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-GATE",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-ROC",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-IOB",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-DALI",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-VIS",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "L-PAD",
          "vendor": "Loytec",
          "versions": [
            {
              "lessThanOrEqual": "8.4.16",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Daniel Hulliger, armasuisse CYD Campus"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Damian Pfammatter, armasuisse CYD Campus"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Improper Link Resolution (CWE-59)\u0026nbsp;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`."
            }
          ],
          "value": "Improper Link Resolution (CWE-59)\u00a0in `/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`."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-122",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-122 Privilege Abuse"
            }
          ]
        },
        {
          "capecId": "CAPEC-233",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-233 Privilege Escalation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 9.2,
            "baseSeverity": "CRITICAL",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59 Improper link resolution before file access (\u0027link following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-24T13:57:56.691Z",
        "orgId": "455daabc-a392-441d-aa46-37d35189897c",
        "shortName": "NCSC.ch"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.loytec.com/support/product-security/advisories/8520-dibt-cve-20260526-0002-symlink-following-in-chown-chmod-critical"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Upgrade to firmware 8.4.18."
            }
          ],
          "value": "Upgrade to firmware 8.4.18."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Loytec LINX firmware: Improper Link Resolution in /usr/bin/larm_starter",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "455daabc-a392-441d-aa46-37d35189897c",
    "assignerShortName": "NCSC.ch",
    "cveId": "CVE-2026-12503",
    "datePublished": "2026-07-24T13:57:56.691Z",
    "dateReserved": "2026-06-17T09:48:11.206Z",
    "dateUpdated": "2026-07-24T14:57:47.202Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-4P7F-6RPF-28MQ

CVE-2026-12503 (GCVE-0-2026-12503)

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Sightings

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