{
  "schema_version": "1.5.0",
  "id": "CURL-CVE-2017-8816",
  "aliases": [
    "CVE-2017-8816"
  ],
  "summary": "NTLM buffer overflow via integer overflow",
  "modified": "2026-04-25T17:48:46.00Z",
  "database_specific": {
    "package": "curl",
    "affects": "both",
    "URL": "https://curl.se/docs/CVE-2017-8816.json",
    "www": "https://curl.se/docs/CVE-2017-8816.html",
    "CWE": {
      "id": "CWE-131",
      "desc": "Incorrect Calculation of Buffer Size"
    },
    "last_affected": "7.56.1",
    "severity": "Medium"
  },
  "published": "2017-11-29T08:00:00.00Z",
  "affected": [
    {
      "ranges": [
        {
           "type": "SEMVER",
           "events": [
             {"introduced": "7.36.0"},
             {"fixed": "7.57.0"}
           ]
        },
        {
           "type": "GIT",
           "repo": "https://github.com/curl/curl.git",
           "events": [
             {"introduced": "86724581b6c02d160b52f817550cfdfc9c93af62"},
             {"fixed": "7f2a1df6f5fc598750b2c6f34465c8d924db28cc"}
           ]
        }
      ],
      "versions": [
        "7.56.1", "7.56.0", "7.55.1", "7.55.0", "7.54.1", "7.54.0", "7.53.1", 
        "7.53.0", "7.52.1", "7.52.0", "7.51.0", "7.50.3", "7.50.2", "7.50.1", 
        "7.50.0", "7.49.1", "7.49.0", "7.48.0", "7.47.1", "7.47.0", "7.46.0", 
        "7.45.0", "7.44.0", "7.43.0", "7.42.1", "7.42.0", "7.41.0", "7.40.0", 
        "7.39.0", "7.38.0", "7.37.1", "7.37.0", "7.36.0"
      ]
    }
  ],
  "credits": [
    {
      "name": "Alex Nichols",
      "type": "FINDER"
    },
    {
      "name": "Daniel Stenberg",
      "type": "REMEDIATION_DEVELOPER"
    }
  ],
  "details": "libcurl contains a buffer overrun flaw in the NTLM authentication code.\n\nThe internal function `Curl_ntlm_core_mk_ntlmv2_hash` sums up the lengths of\nthe username + password (= SUM) and multiplies the sum by two (= SIZE) to\nfigure out how large storage to allocate from the heap.\n\nThe SUM value is subsequently used to iterate over the input and generate\noutput into the storage buffer. On systems with a 32-bit `size_t`, the math to\ncalculate SIZE triggers an integer overflow when the combined lengths of the\nusername and password is larger than 2GB (2^31 bytes). This integer overflow\nusually causes a tiny buffer to actually get allocated instead of the intended\nhuge one, making the use of that buffer end up in a buffer overrun."
}