UBUNTU-CVE-2019-18277

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    UBUNTU-CVE-2019-18277

    Published: 23 Oct 2019Last Modified: 4 Feb 2026
    Upstream:
    CVE-2019-18277
    Aliases:
    USN-4174-1

    Summary:

    Details: A flaw was found in HAProxy before 2.0.6. In legacy mode, messages featuring a transfer-encoding header missing the "chunked" value were not being correctly rejected. The impact was limited but if combined with the "http-reuse always" setting, it could be used to help construct an HTTP request smuggling attack against a vulnerable component employing a lenient parser that would ignore the content-length header as soon as it saw a transfer-encoding one (even if not entirely valid according to the specification).

    References: https://ubuntu.com/security/CVE-2019-18277, https://nathandavison.com/blog/haproxy-http-request-smuggling, https://www.mail-archive.com/[email protected]/msg34926.html, https://ubuntu.com/security/notices/USN-4174-1, https://www.cve.org/CVERecord?id=CVE-2019-18277

    Affected packages

    Package

    Name: haproxy

    Purl: pkg:deb/ubuntu/[email protected]?arch=source&distro=xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1.6.3-1ubuntu0.3

    Affected versions

    1.5.14-1
    1.5.15-1

    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
    UBUNTU-CVE-2019-18277 | CVE-DB