Vulnerability-Lookup

GHSA-5CXQ-44W6-64MX

Vulnerability from github – Published: 2026-09-29 18:32 – Updated: 2026-09-29 18:32

Details

A TFTP server that answers with a short ERROR packet makes the client read up to 64 bytes past the

received datagram.

Each receive path checks only that the datagram is at least four bytes long (nxd_tftp_client.c:1229,

1521, 1984). When the opcode is NX_TFTP_CODE_ERROR the message string is copied with a loop whose

only limits are the destination buffer and a NUL byte:




/* addons/tftp/nxd_tftp_client.c:1769 */



for (i = 0; (i < (sizeof(tftp_client_ptr -> nx_tftp_client_error_string) - 1)) && (*buffer_ptr); i++)

Nothing compares buffer_ptr against nx_packet_append_ptr. An ERROR packet that carries no

terminating NUL, which a server controls completely, walks the loop off the end of the packet until

it happens to meet a zero byte or fills the 64 byte destination.




ERROR: AddressSanitizer: heap-buffer-overflow



READ of size 1 at 0x60d0000000c8 thread T4

    #0 _nxd_tftp_client_file_read  addons/tftp/nxd_tftp_client.c:1769


0x60d0000000c8 is 0 bytes to the right of 136-byte region

The open path has the same loop at :1327 and reports the same way. What is read lands in

nx_tftp_client_error_string, which the application is expected to display or log, so adjacent

packet pool memory ends up in whatever the device does with the error text.

Add (buffer_ptr < packet_ptr -> nx_packet_append_ptr) to the loop condition in all three paths.

Severity

6.9 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-102721"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-29T18:17:11Z",
    "severity": "MODERATE"
  },
  "details": "A TFTP server that answers with a short ERROR packet makes the client read up to 64 bytes past the\n\n\n\nreceived datagram.\n\n\n\nEach receive path checks only that the datagram is at least four bytes long (nxd_tftp_client.c:1229,\n\n\n\n1521, 1984). When the opcode is NX_TFTP_CODE_ERROR the message string is copied with a loop whose\n\n\n\nonly limits are the destination buffer and a NUL byte:\n\n\n\n```c\n\n\n\n/* addons/tftp/nxd_tftp_client.c:1769 */\n\n\n\nfor (i = 0; (i \u003c (sizeof(tftp_client_ptr -\u003e nx_tftp_client_error_string) - 1)) \u0026\u0026 (*buffer_ptr); i++)\n\n\n\n```\n\n\n\nNothing compares `buffer_ptr` against `nx_packet_append_ptr`. An ERROR packet that carries no\n\n\n\nterminating NUL, which a server controls completely, walks the loop off the end of the packet until\n\n\n\nit happens to meet a zero byte or fills the 64 byte destination.\n\n\n\n```\n\n\n\nERROR: AddressSanitizer: heap-buffer-overflow\n\n\n\nREAD of size 1 at 0x60d0000000c8 thread T4\n\n    #0 _nxd_tftp_client_file_read  addons/tftp/nxd_tftp_client.c:1769\n\n\n0x60d0000000c8 is 0 bytes to the right of 136-byte region\n\n\n\n```\n\n\n\nThe open path has the same loop at :1327 and reports the same way. What is read lands in\n\n\n\n`nx_tftp_client_error_string`, which the application is expected to display or log, so adjacent\n\n\n\npacket pool memory ends up in whatever the device does with the error text.\n\n\n\nAdd `(buffer_ptr \u003c packet_ptr -\u003e nx_packet_append_ptr)` to the loop condition in all three paths.",
  "id": "GHSA-5cxq-44w6-64mx",
  "modified": "2026-09-29T18:32:01Z",
  "published": "2026-09-29T18:32:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-wvc9-5m9h-rvxc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-102721"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/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-2026-102721 (GCVE-0-2026-102721)

Vulnerability from cvelistv5 – Published: 2026-09-29 17:47 – Updated: 2026-09-29 18:36

Summary

A TFTP server that answers with a short ERROR packet makes the client read up to 64 bytes past the received datagram. Each receive path checks only that the datagram is at least four bytes long (nxd_tftp_client.c:1229, 1521, 1984). When the opcode is NX_TFTP_CODE_ERROR the message string is copied with a loop whose only limits are the destination buffer and a NUL byte: ```c /* addons/tftp/nxd_tftp_client.c:1769 */ for (i = 0; (i < (sizeof(tftp_client_ptr -> nx_tftp_client_error_string) - 1)) && (*buffer_ptr); i++) ``` Nothing compares `buffer_ptr` against `nx_packet_append_ptr`. An ERROR packet that carries no terminating NUL, which a server controls completely, walks the loop off the end of the packet until it happens to meet a zero byte or fills the 64 byte destination. ``` ERROR: AddressSanitizer: heap-buffer-overflow READ of size 1 at 0x60d0000000c8 thread T4 #0 _nxd_tftp_client_file_read addons/tftp/nxd_tftp_client.c:1769 0x60d0000000c8 is 0 bytes to the right of 136-byte region ``` The open path has the same loop at :1327 and reports the same way. What is read lands in `nx_tftp_client_error_string`, which the application is expected to display or log, so adjacent packet pool memory ends up in whatever the device does with the error text. Add `(buffer_ptr < packet_ptr -> nx_packet_append_ptr)` to the loop condition in all three paths.

Severity

6.9 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-29 18:35 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

eclipse mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/eclipse-threadx/netxduo/securi…

Impacted products

1 product

Vendor	Product	Version
Eclipse Foundation	NetX Duo	Affected: 0 , ≤ 6.5.1 (semver)

Credits

L0stHeart

Show details on NVD website

JSON

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                "role": "CISA Coordinator",
                "timestamp": "2026-09-29T18:35:29.043788Z",
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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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.

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-5CXQ-44W6-64MX

CVE-2026-102721 (GCVE-0-2026-102721)

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