CVE-2026-45699 (GCVE-0-2026-45699)

Vulnerability from cvelistv5 – Published: 2026-08-14 19:05 – Updated: 2026-08-14 19:06
VLAI
Title
Netatalk has Integer Underflow → Stack Buffer Overflow in copydir()
Summary
Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
References
Impacted products
Vendor Product Version
Netatalk netatalk Affected: >= 3.1.19, < 4.4.3
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{
  "containers": {
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      "affected": [
        {
          "product": "netatalk",
          "vendor": "Netatalk",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.1.19, \u003c 4.4.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a  stack-based buffer overflow exists in the copydir() function of Netatalk\u0027s afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library\u0027s renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de-\u003ed_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-191",
              "description": "CWE-191: Integer Underflow (Wrap or Wraparound)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-14T19:06:22.102Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Netatalk/netatalk/security/advisories/GHSA-fphv-pf29-p77m",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Netatalk/netatalk/security/advisories/GHSA-fphv-pf29-p77m"
        },
        {
          "name": "https://github.com/Netatalk/netatalk/releases/tag/netatalk-4-4-3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Netatalk/netatalk/releases/tag/netatalk-4-4-3"
        }
      ],
      "source": {
        "advisory": "GHSA-fphv-pf29-p77m",
        "discovery": "UNKNOWN"
      },
      "title": "Netatalk has Integer Underflow \u2192 Stack Buffer Overflow in copydir()"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45699",
    "datePublished": "2026-08-14T19:05:46.906Z",
    "dateReserved": "2026-05-13T04:38:01.165Z",
    "dateUpdated": "2026-08-14T19:06:22.102Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-45699",
      "date": "2026-08-15",
      "epss": "0.00335",
      "percentile": "0.26445"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-45699\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-08-14T19:17:18.267\",\"lastModified\":\"2026-08-14T19:17:18.267\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a  stack-based buffer overflow exists in the copydir() function of Netatalk\u0027s afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library\u0027s renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de-\u003ed_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"Netatalk\",\"product\":\"netatalk\",\"versions\":[{\"version\":\"\u003e= 3.1.19, \u003c 4.4.3\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.6,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-191\"}]}],\"references\":[{\"url\":\"https://github.com/Netatalk/netatalk/releases/tag/netatalk-4-4-3\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/Netatalk/netatalk/security/advisories/GHSA-fphv-pf29-p77m\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}



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