CURL-CVE-2015-3236

    Dashboard / Vulnerabilities / CURL-CVE-2015-3236

    CURL-CVE-2015-3236

    Published: 17 Jun 2015Last Modified: 19 May 2026
    Aliases:

    Summary: lingering HTTP credentials in connection reuse

    Details: libcurl can wrongly send HTTP credentials when reusing connections. libcurl allows applications to set credentials for the upcoming transfer with HTTP Basic authentication, like with `CURLOPT_USERPWD` for example. Name and password. Like all other libcurl options the credentials are sticky and are kept associated with the "handle" until something is made to change the situation. Further, libcurl offers a `curl_easy_reset()` function that resets a handle back to its pristine state in terms of all settable options. A reset is of course also supposed to clear the credentials. A reset is typically used to clear up the handle and prepare it for a new, possibly unrelated, transfer. Within such a handle, libcurl can also store a set of previous connections in case a second transfer is requested to a hostname for which an existing connection is already kept alive. With this flaw present, using the handle even after a reset would make libcurl accidentally use those credentials in a subsequent request if done to the same hostname and connection as was previously accessed. An example case would be first requesting a password protected resource from one section of a website, and then do a second request of a public resource from a completely different part of the site without authentication. This flaw would then inadvertently leak the credentials in the second request.

    References:

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 7.40.0
    Fixed -7.43.0

    Affected versions

    7.42.1
    7.42.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CURL-CVE-2015-3236 | CVE-DB