Vulnerability-Lookup

CVE-2026-13479 (GCVE-0-2026-13479)

Vulnerability from cvelistv5 – Published: 2026-08-26 14:03 – Updated: 2026-08-26 15:44

Title

Out-of-bounds read in LoRaWAN clock-sync AppTimeAns downlink handler

Summary

The LoRaWAN application-layer clock-synchronization service parses downlinks in clock_sync_package_callback() (subsys/lorawan/services/clock_sync.c). Its command loop only guarantees that the one-byte command id is in bounds; for the CLOCK_SYNC_CMD_APP_TIME (AppTimeAns) command the handler then reads a 4-byte time correction via sys_get_le32() plus a 1-byte token without checking that 5 bytes remain in the receive buffer (len - rx_pos). A short or crafted AppTimeAns therefore reads up to 5 bytes past the end of the decrypted payload. The payload (rx_buf/len) is the decrypted application frame delivered to the registered downlink callback (mcps_indication->Buffer/BufferSize). Reaching the handler requires a frame on the clock-sync port that passes LoRaWAN's MAC integrity check and FRMPayload decryption, so the practical attacker is a malicious or compromised network/application server (the designated sender of AppTimeAns) or a party holding the session keys, rather than an arbitrary radio listener. The over-read is bounded: the backing store is a fixed 255-byte static buffer, so the few stray bytes do not fault, and the read values (time_correction, token) are used only internally and never transmitted, so there is no disclosure to the attacker and no crash. The sole effect is that a stale token matching ctx.req_token can apply a garbage time_correction to the device's own clock offset (ctx.time_offset), a minor integrity impact confined to the victim's time estimate. The fix adds an explicit length check that drops a too-short AppTimeAns. Note the sibling one-byte reads in the periodicity and force-resync handlers remain unguarded with the same negligible impact.

Severity

3.1 (Low)


                        
                          CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-26 15:44 UTC

CWE

CWE-125 - bounds

Assigner

zephyr mitre root

References

2 references

URL	Tags
https://github.com/zephyrproject-rtos/zephyr/comm…	patch
https://github.com/zephyrproject-rtos/zephyr/secu…

Impacted products

1 product

Vendor	Product	Version	CPE status
zephyrproject	zephyr	Affected: 3.3.0 , < 4.4.2 (semver)	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-13479

Vulnerability from fkie_nvd - Published: 2026-08-26 15:16 - Updated: 2026-08-26 16:59

Severity

3.1 (Low) - CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Summary

References

	URL	Tags
	vulnerabilities@zephyrproject.org	https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5
	vulnerabilities@zephyrproject.org	https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "defaultStatus": "unaffected",
          "packageName": "zephyr",
          "product": "zephyr",
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            "subsys/lorawan/services/clock_sync.c"
          ],
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            {
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              "status": "affected",
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            }
          ]
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      ],
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    }
  ],
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    }
  ],
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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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

CVE-2026-13479 (GCVE-0-2026-13479)

FKIE_CVE-2026-13479

Tags

Sightings

Nomenclature