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Medium

wrong reuse of connections

Type: advisorySources: OSV

libcurl can in some circumstances reuse the wrong connection when asked to do transfers using other protocols than HTTP and FTP. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to an error in the code, a transfer that was initiated by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. The existing logic only worked well enough for HTTP and FTP, while all other network protocols were silently, but erroneously, assumed to work like HTTP. Protocols that use connection oriented authentication need a new connection when new credentials are used. Affected protocols include: SCP, SFTP, POP3(S), IMAP(S), SMTP(S) and LDAP(S). Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API). (This problem is similar to a problem previously reported to NTLM HTTP connections, named [CVE-2014-0015](CVE-2014-0015.html))

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2014-0138
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 09:35 UTC · Revision 1

Source evidence

wrong reuse of connections

core-osv · Original source

Published 26 Mar 2014, 08:00 UTC

libcurl can in some circumstances reuse the wrong connection when asked to do transfers using other protocols than HTTP and FTP. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to an error in the code, a transfer that was initiated by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. The existing logic only worked well enough for HTTP and FTP, while all other network protocols were silently, but erroneously, assumed to work like HTTP. Protocols that use connection oriented authentication need a new connection when new credentials are used. Affected protocols include: SCP, SFTP, POP3(S), IMAP(S), SMTP(S) and LDAP(S). Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API). (This problem is similar to a problem previously reported to NTLM HTTP connections, named [CVE-2014-0015](CVE-2014-0015.html))

osv:CURL-CVE-2014-0138
Complete source record
{
  "id": "69243d2910572624abf0a79f22dc921c5baae934b488a4127515c8a7f1aff2e2",
  "url": "https://osv.dev/vulnerability/CURL-CVE-2014-0138",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "wrong reuse of connections",
    "summary": "libcurl can in some circumstances reuse the wrong connection when asked to do transfers using other protocols than HTTP and FTP. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to an error in the code, a transfer that was initiated by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. The existing logic only worked well enough for HTTP and FTP, while all other network protocols were silently, but erroneously, assumed to work like HTTP. Protocols that use connection oriented authentication need a new connection when new credentials are used. Affected protocols include: SCP, SFTP, POP3(S), IMAP(S), SMTP(S) and LDAP(S). Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API). (This problem is similar to a problem previously reported to NTLM HTTP connections, named [CVE-2014-0015](CVE-2014-0015.html))",
    "evidence": "osv:CURL-CVE-2014-0138",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CURL-CVE-2014-0138",
      "aliases": [
        "CURL-CVE-2014-0138",
        "CVE-2014-0138"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "7.10.6"
                },
                {
                  "fixed": "7.36.0"
                }
              ]
            }
          ],
          "versions": [
            "7.35.0",
            "7.34.0",
            "7.33.0",
            "7.32.0",
            "7.31.0",
            "7.30.0",
            "7.29.0",
            "7.28.1",
            "7.28.0",
            "7.27.0",
            "7.26.0",
            "7.25.0",
            "7.24.0",
            "7.23.1",
            "7.23.0",
            "7.22.0",
            "7.21.7",
            "7.21.6",
            "7.21.5",
            "7.21.4",
            "7.21.3",
            "7.21.2",
            "7.21.1",
            "7.21.0",
            "7.20.1",
            "7.20.0",
            "7.19.7",
            "7.19.6",
            "7.19.5",
            "7.19.4",
            "7.19.3",
            "7.19.2",
            "7.19.1",
            "7.19.0",
            "7.18.2",
            "7.18.1",
            "7.18.0",
            "7.17.1",
            "7.17.0",
            "7.16.4",
            "7.16.3",
            "7.16.2",
            "7.16.1",
            "7.16.0",
            "7.15.5",
            "7.15.4",
            "7.15.3",
            "7.15.2",
            "7.15.1",
            "7.15.0",
            "7.14.1",
            "7.14.0",
            "7.13.2",
            "7.13.1",
            "7.13.0",
            "7.12.3",
            "7.12.2",
            "7.12.1",
            "7.12.0",
            "7.11.2",
            "7.11.1",
            "7.11.0",
            "7.10.8",
            "7.10.7",
            "7.10.6"
          ],
          "database_specific": {
            "source": "https://curl.se/docs/CURL-CVE-2014-0138.json"
          }
        }
      ],
      "modified": "2026-10-24T23:17:46Z",
      "provider": "osv",
      "references": [],
      "provider_metadata": {
        "CWE": {
          "id": "CWE-305",
          "desc": "Authentication Bypass by Primary Weakness"
        },
        "URL": "https://curl.se/docs/CVE-2014-0138.json",
        "www": "https://curl.se/docs/CVE-2014-0138.html",
        "affects": "both",
        "package": "curl",
        "severity": "Medium",
        "last_affected": "7.35.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2014-0138",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 444191,
  "published_at": "2014-03-26T08:00:00+00:00"
}