ubuntu-cve-2025-57632
Vulnerability from osv_ubuntu
Published
2025-09-25 20:15
Modified
2026-05-20 15:22
Summary
Details

libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2_add_iovector() to append to a fixed-size iovec array without checking the upper bound of v->niov (SMB2_MAX_VECTORS=256). An attacker can craft responses with many chained PDUs to overflow v->niov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2_OPLOCK_BREAK path bypasses message ID validation.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libsmb2-6",
            "binary_version": "6.2+dfsg-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libsmb2",
        "purl": "pkg:deb/ubuntu/libsmb2@6.2+dfsg-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.2+dfsg-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libsmb2-6",
            "binary_version": "6.2+dfsg-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libsmb2",
        "purl": "pkg:deb/ubuntu/libsmb2@6.2+dfsg-3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.2+dfsg-2",
        "6.2+dfsg-3"
      ]
    }
  ],
  "aliases": [],
  "details": "libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2_add_iovector() to append to a fixed-size iovec array without checking the upper bound of v-\u003eniov (SMB2_MAX_VECTORS=256). An attacker can craft responses with many chained PDUs to overflow v-\u003eniov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2_OPLOCK_BREAK path bypasses message ID validation.",
  "id": "UBUNTU-CVE-2025-57632",
  "modified": "2026-05-20T15:22:56Z",
  "published": "2025-09-25T20:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-57632"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-57632"
    },
    {
      "type": "REPORT",
      "url": "https://gist.github.com/ZjW1nd/0b95b63307ceee7890e88e4abc6f041e"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/sahlberg/libsmb2"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/sahlberg/libsmb2/blob/master/lib/compat.c#L569"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-57632"
  ]
}



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