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osec-2016-01
Vulnerability from osv_ocaml
Published
2016-04-29 00:18
Modified
2026-01-01 12:00
Summary
Buffer overflow and information leak in OCaml < 4.03.0
Details

Bug description

OCaml versions 4.02.3 and earlier have a runtime bug that, on 64-bit platforms, causes sizes arguments to an internal memmove call to be sign-extended from 32 to 64-bits before being passed to the memmove function.

This leads arguments between 2GiB and 4GiB to be interpreted as larger than they are (specifically, a bit below 2^64), causing a buffer overflow.

Arguments between 4GiB and 6GiB are interpreted as 4GiB smaller than they should be, causing a possible information leak.

This commit fixes the bug: https://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74#diff-a97df53e3ebc59bb457191b496c90762 The function caml_bit_string is called indirectly from such functions as String.copy. String.copy for instance is supposed to be a "safe" function for which OCaml's memory safety guarantees apply.

Severity
9.1 (Critical)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Credits
Radek Micek
Damien Doligez
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "opam_constraint": "ocaml {\u003c \"4.03.0\"}"
      },
      "package": {
        "ecosystem": "opam",
        "name": "ocaml",
        "purl": "pkg:opam/ocaml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.03.0"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "659615c7b100a89eafe6253e7a5b9d84d0e8df74"
            }
          ],
          "repo": "https://github.com/ocaml/ocaml",
          "type": "GIT"
        }
      ],
      "versions": [
        "3.07",
        "3.07+1",
        "3.07+2",
        "3.08.0",
        "3.08.1",
        "3.08.2",
        "3.08.3",
        "3.08.4",
        "3.09.0",
        "3.09.1",
        "3.09.2",
        "3.09.3",
        "3.10.0",
        "3.10.1",
        "3.10.2",
        "3.11.0",
        "3.11.1",
        "3.11.2",
        "3.12.0",
        "3.12.1",
        "4.00.0",
        "4.00.1",
        "4.01.0",
        "4.02.0",
        "4.02.1",
        "4.02.2",
        "4.02.3",
        "4.02.4"
      ]
    }
  ],
  "aliases": [
    "CVE-2015-8869"
  ],
  "credits": [
    {
      "name": "Radek Micek",
      "type": "REPORTER"
    },
    {
      "name": "Damien Doligez",
      "type": "REMEDIATION_DEVELOPER"
    }
  ],
  "database_specific": {
    "cwe": [
      "CWE-119",
      "CWE-200"
    ],
    "human_link": "https://github.com/ocaml/security-advisories/tree/main/advisories/2016/OSEC-2016-01.md",
    "osv": "https://github.com/ocaml/security-advisories/tree/generated-osv/2016/OSEC-2016-01.json"
  },
  "details": "## Bug description\n\nOCaml versions 4.02.3 and earlier have a runtime bug that, on 64-bit platforms, causes sizes arguments to an internal memmove call to be sign-extended from 32 to 64-bits before being passed to the memmove function.\n\nThis leads arguments between 2GiB and 4GiB to be interpreted as larger than they are (specifically, a bit below 2^64), causing a buffer overflow.\n\nArguments between 4GiB and 6GiB are interpreted as 4GiB smaller than they should be, causing a possible information leak.\n\nThis commit fixes the bug:\nhttps://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74#diff-a97df53e3ebc59bb457191b496c90762\nThe function caml_bit_string is called indirectly from such functions as String.copy. String.copy for instance is supposed to be a \"safe\" function for which OCaml\u0027s memory safety guarantees apply.",
  "id": "OSEC-2016-01",
  "modified": "2026-01-01T12:00:00Z",
  "published": "2016-04-29T00:18:22Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://github.com/ocaml/ocaml/issues/7003"
    }
  ],
  "schema_version": "1.7.4",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Buffer overflow and information leak in OCaml \u003c 4.03.0"
}



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