CURL-CVE-2017-8816

    Dashboard / Vulnerabilities / CURL-CVE-2017-8816

    CURL-CVE-2017-8816

    Published: 29 Nov 2017Last Modified: 27 May 2026
    Aliases:

    Summary: NTLM buffer overflow via integer overflow

    Details: libcurl contains a buffer overrun flaw in the NTLM authentication code. The internal function `Curl_ntlm_core_mk_ntlmv2_hash` sums up the lengths of the username + password (= SUM) and multiplies the sum by two (= SIZE) to figure out how large storage to allocate from the heap. The SUM value is subsequently used to iterate over the input and generate output into the storage buffer. On systems with a 32-bit `size_t`, the math to calculate SIZE triggers an integer overflow when the combined lengths of the username and password is larger than 2GB (2^31 bytes). This integer overflow usually causes a tiny buffer to actually get allocated instead of the intended huge one, making the use of that buffer end up in a buffer overrun.

    References:

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 7.36.0
    Fixed -7.57.0

    Affected versions

    7.56.1
    7.56.0

    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