CVE-2026-13479

{
  "id": "CVE-2026-13479",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-26T15:16:42.693",
  "lastModified": "2026-11-04T05:18:42.320",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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.\n\nThe 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.\n\nThe 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."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "zephyrproject",
          "product": "zephyr",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "packageName": "zephyr",
          "programFiles": [
            "subsys/lorawan/services/clock_sync.c"
          ],
          "versions": [
            {
              "version": "3.3.0",
              "lessThan": "4.3.2",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "4.4.0",
              "lessThan": "4.4.2",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
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        "source": "[email protected]",
        "type": "Secondary",
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          "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "baseScore": 3.1,
          "baseSeverity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
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        "exploitabilityScore": 1.6,
        "impactScore": 1.4
      },
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        "type": "Primary",
        "cvssData": {
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          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
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      }
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    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-26T15:44:08.607894Z",
          "id": "CVE-2026-13479",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
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              "technicalImpact": "partial"
            }
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          "role": "CISA Coordinator",
          "version": "2.0.3"
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  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
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  "configurations": [
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          "cpeMatch": [
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  "references": [
    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5",
      "source": "[email protected]",
      "tags": [
        "Patch"
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    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Patch",
        "Vendor Advisory"
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    }
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}