GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

GCVE-1988-2026-0203

Vulnerability from gna-1988 – Published: 2026-09-08 07:57 – Updated: 2026-09-09 10:09
VLAI
Title
[SYSS-2025-011] Linksys MX9600/MX4200 - OS Command Injection
Summary
Advisory ID:               SYSS-2025-011 Product:                   MR9600, MX4200 (and potentially others) Manufacturer:              Linksys Tested Version(s):         1.0.4.205530 for MR9600, 1.0.13.210200 for MX4200 Vulnerability Type:        OS Command Injection (CWE-78) Risk Level:                High Solution Status:           Open Manufacturer Notification: 2025-03-18 Solution Date:             - Public Disclosure:         2026-02-12 CVE Reference:             Not yet assigned Author of Advisory:        Christian Zäske, SySS GmbH ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Overview: Linksys MX4200 is a Wi-Fi mesh router targeting home users. The manufacturer describes the product as follows (see [1]): "This router supports the latest Wi-Fi® 6 (802.11ax) standard for next-level streaming and gaming. Its powerful WiFi 6 mesh coverage offers faster WiFi performance for lag-free online gaming and simultaneous streaming to every device and corner of your home." Due to missing neutralization of special elements, OS commands can be injected via the update functionality of a TLS-SRP connection, which is normally used for configuring devices inside the mesh network. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vulnerability Details: The Linksys MX4200 (and other models) provides a service (sct_server binary) running on TCP port 6060, which is used to integrate other mesh devices into the network. The service accepts TLS-SRP connections with a username and password. The service supports an update request, which can be used to set "syscfg" variables on the device. The script "/tmp/cron/cron.everyminute/offline-notifier.cron" is executed every minute and sets "syscfg" variables containing "node-off" as environment variables using the following lines:   VARS="$(syscfg show |           grep node-off |           sed -r "s/^[^:]+:://g" |           while read i; do               echo "$i;"           done)"   eval $VARS Usually, the variable "VARS" is set to a value similar to the following:   $ syscfg show | grep node-off   node-off::min_offline_time=3   node-off::enabled=1   node-off::cache_dir=/tmp/msg   node-off::enable_cloud=1   node-off::debug=0 By using the service on port 6060, an update request can be sent to the device, which can be used to set an arbitrary "syscfg" entry. If this entry contains ";", OS commands can be injected into the "VARS" variable, which will be used by eval. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Proof of Concept (PoC): Using the "tlslite-ng" library, the following Python code will result in the LED indicator at the top of the device turning yellow, indicating that the OS command got successfully executed:   from socket import *   from tlslite.api import *   sock = socket.socket(AF_INET, SOCK_STREAM)   sock.connect(("192.168.1.1", 6060))   conn = TLSConnection(sock)   conn.handshakeClientSRP(srp_username, srp_pass) conn.sendall(bytes.fromhex("4f53435479e0b43120fcf435000000600000")) This code results in the following "syscfg" value to be set:   $ syscfg show | grep SySS   node-off::SySS=; combo_solid yellow on When parsed by the script "offline-notifier.cron", the following line will be executed by eval, resulting in the indicator LED turning yellow after a maximum of 60 seconds: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solution: There is no known solution yet. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclosure Timeline: 2025-01-30: Vulnerability discovered 2025-03-18: Vulnerability reported to manufacturer 2025-04-07: First response from manufacturer 2025-04-14: Requested an update from manufacturer 2025-05-06: Acknowledgment of vulnerabilities by the manufacturer 2026-02-12: Public disclosure ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ References: [1] Product website for Linksys MX4200     https://support.linksys.com/kb/article/952-en/ [2] SySS Security Advisory SYSS-2025-011 https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2025-011.txt [3] SySS Responsible Disclosure Policy     https://www.syss.de/en/responsible-disclosure-policy ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Credits: This security vulnerability was found by Christian Zäske of SySS GmbH. E-Mail: christian.zaeske () syss de Key ID: 0x7B00D164A32F9AC9 Key Fingerprint: 51D4 6E9B 3C29 7347 AC01 0F5A 7B00 D164 A32F 9AC9 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclaimer: The information provided in this security advisory is provided "as is" and without warranty of any kind. Details of this security advisory may be updated in order to provide as accurate information as possible. The latest version of this security advisory is available on the SySS website. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Copyright: Creative Commons - Attribution (by) - Version 3.0 URL: https://creativecommons.org/licenses/by/3.0/deed.en _______________________________________________ Sent through the Full Disclosure mailing list https://nmap.org/mailman/listinfo/fulldisclosure Web Archives & RSS: https://seclists.org/fulldisclosure/
Severity
No CVSS data available.
CWE
Impacted products
Vendor Product Version CPE status
Linksys Linksys MX9600/MX4200 - Affected: unknown
guessed Create a notification for this product.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "Linksys MX9600/MX4200 -",
          "vendor": "Linksys",
          "versions": [
            {
              "status": "affected",
              "version": "unknown"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Christian Z\u00e4ske via Fulldisclosure"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Advisory ID:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0SYSS-2025-011\nProduct:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0MR9600, MX4200 (and potentially others)\nManufacturer:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Linksys\n\nTested Version(s):\u00a0 \u00a0 \u00a0 \u00a0 \u00a01.0.4.205530 for MR9600, 1.0.13.210200 for MX4200\nVulnerability Type:\u00a0 \u00a0 \u00a0 \u00a0 OS Command Injection (CWE-78)\nRisk Level:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 High\nSolution Status:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Open\nManufacturer Notification: 2025-03-18\nSolution Date:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-\nPublic Disclosure:\u00a0 \u00a0 \u00a0 \u00a0 \u00a02026-02-12\nCVE Reference:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Not yet assigned\nAuthor of Advisory:\u00a0 \u00a0 \u00a0 \u00a0 Christian Z\u00e4ske, SySS GmbH\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nOverview:\n\nLinksys MX4200 is a Wi-Fi mesh router targeting home users.\n\nThe manufacturer describes the product as follows (see [1]):\n\n\"This router supports the latest Wi-Fi\u00ae 6 (802.11ax) standard for\nnext-level streaming and gaming. Its powerful WiFi 6 mesh coverage\noffers faster WiFi performance for lag-free online gaming and\nsimultaneous streaming to every device and corner of your home.\"\n\nDue to missing neutralization of special elements, OS commands can\nbe injected via the update functionality of a TLS-SRP connection,\nwhich is normally used for configuring devices inside the mesh\nnetwork.\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nVulnerability Details:\n\nThe Linksys MX4200 (and other models) provides a service (sct_server\nbinary) running on TCP port 6060, which is used to integrate other mesh\ndevices into the network. The service accepts TLS-SRP connections with\na username and password.\n\nThe service supports an update request, which can be used to set\n\"syscfg\" variables on the device. The script\n\"/tmp/cron/cron.everyminute/offline-notifier.cron\" is executed every\nminute and sets \"syscfg\" variables containing \"node-off\" as environment\nvariables using the following lines:\n\n\u00a0 VARS=\"$(syscfg show |\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 grep node-off |\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 sed -r \"s/^[^:]+:://g\" |\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 while read i; do\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 echo \"$i;\"\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 done)\"\n\u00a0 eval $VARS\n\nUsually, the variable \"VARS\" is set to a value similar to the following:\n\n\u00a0 $ syscfg show | grep node-off\n\n\u00a0 node-off::min_offline_time=3\n\u00a0 node-off::enabled=1\n\u00a0 node-off::cache_dir=/tmp/msg\n\u00a0 node-off::enable_cloud=1\n\u00a0 node-off::debug=0\n\n\n\nBy using the service on port 6060, an update request can be sent to the\ndevice, which can be used to set an arbitrary \"syscfg\" entry. If this\nentry contains \";\", OS commands can be injected into the \"VARS\"\nvariable, which will be used by eval.\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nProof of Concept (PoC):\n\nUsing the \"tlslite-ng\" library, the following Python code will result\nin the LED indicator at the top of the device turning yellow, indicating\nthat the OS command got successfully executed:\n\n\u00a0 from socket import *\n\u00a0 from tlslite.api import *\n\n\u00a0 sock = socket.socket(AF_INET, SOCK_STREAM)\n\u00a0 sock.connect((\"192.168.1.1\", 6060))\n\n\u00a0 conn = TLSConnection(sock)\n\u00a0 conn.handshakeClientSRP(srp_username, srp_pass)\n\nconn.sendall(bytes.fromhex(\"4f53435479e0b43120fcf435000000600000\"))\n\n\nThis code results in the following \"syscfg\" value to be set:\n\n\u00a0 $ syscfg show | grep SySS\n\u00a0 node-off::SySS=; combo_solid yellow on\n\nWhen parsed by the script \"offline-notifier.cron\", the following line\nwill be executed by eval, resulting in the indicator LED turning yellow\nafter a maximum of 60 seconds:\n\n\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nSolution:\n\nThere is no known solution yet.\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nDisclosure Timeline:\n\n2025-01-30: Vulnerability discovered\n2025-03-18: Vulnerability reported to manufacturer\n2025-04-07: First response from manufacturer\n2025-04-14: Requested an update from manufacturer\n2025-05-06: Acknowledgment of vulnerabilities by the manufacturer\n2026-02-12: Public disclosure\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nReferences:\n\n[1] Product website for Linksys MX4200\n\u00a0 \u00a0 https://support.linksys.com/kb/article/952-en/\n[2] SySS Security Advisory SYSS-2025-011\nhttps://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2025-011.txt\n[3] SySS Responsible Disclosure Policy\n\u00a0 \u00a0 https://www.syss.de/en/responsible-disclosure-policy\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nCredits:\n\nThis security vulnerability was found by Christian Z\u00e4ske of SySS\nGmbH.\n\nE-Mail: christian.zaeske () syss de\n\nKey ID: 0x7B00D164A32F9AC9\nKey Fingerprint: 51D4 6E9B 3C29 7347 AC01 0F5A 7B00 D164 A32F 9AC9\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nDisclaimer:\n\nThe information provided in this security advisory is provided \"as is\"\nand without warranty of any kind. Details of this security advisory may\nbe updated in order to provide as accurate information as possible. The\nlatest version of this security advisory is available on the SySS website.\n\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\nCopyright:\n\nCreative Commons - Attribution (by) - Version 3.0\nURL: https://creativecommons.org/licenses/by/3.0/deed.en\n\n_______________________________________________\nSent through the Full Disclosure mailing list\nhttps://nmap.org/mailman/listinfo/fulldisclosure\nWeb Archives \u0026 RSS: https://seclists.org/fulldisclosure/"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-78",
              "description": "CWE-78",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-09T10:09:38Z",
        "orgId": "4e2abfbf-4a2a-4b76-a4e0-d77c18ba156c",
        "shortName": "VULNARCHIVE"
      },
      "references": [
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://vuln.freearchive.org/archive/full-disclosure/2026/Feb/18"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://seclists.org/fulldisclosure/2026/Feb/18"
        },
        {
          "url": "https://creativecommons.org/licenses/by/3.0/deed.en"
        },
        {
          "url": "https://nmap.org/mailman/listinfo/fulldisclosure"
        },
        {
          "url": "https://seclists.org/fulldisclosure/"
        },
        {
          "url": "https://support.linksys.com/kb/article/952-en/"
        },
        {
          "url": "https://www.syss.de/en/responsible-disclosure-policy"
        },
        {
          "url": "https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2025-011.txt"
        }
      ],
      "source": {
        "defect": [
          "https://seclists.org/fulldisclosure/2026/Feb/18"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "[SYSS-2025-011] Linksys MX9600/MX4200 - OS Command Injection",
      "x_gcve": [
        {
          "recordType": "advisory",
          "relationships": [],
          "vulnId": "GCVE-1988-2026-0203",
          "x_vulnarchive": {
            "archiveUrl": "https://vuln.freearchive.org/archive/full-disclosure/2026/Feb/18",
            "automated": true,
            "contentSha256": "531f353f04bac3f2bbcd04494b568489988470502612900246967d7ef58ce0fb",
            "evidenceScore": 8,
            "messageId": "",
            "originalUrl": "https://seclists.org/fulldisclosure/2026/Feb/18",
            "policy": "vulnarchive-1",
            "sourceFormat": "text/html",
            "sourcePublishedAt": "2026-02-12T10:13:22Z"
          }
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "4e2abfbf-4a2a-4b76-a4e0-d77c18ba156c",
    "assignerShortName": "VULNARCHIVE",
    "datePublished": "2026-09-08T07:57:42Z",
    "dateUpdated": "2026-09-09T10:09:38Z",
    "state": "PUBLISHED",
    "vulnId": "GCVE-1988-2026-0203"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • 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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Loading…