UBUNTU-CVE-2020-11996

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    UBUNTU-CVE-2020-11996

    Published: 26 Jun 2020Last Modified: 15 Jul 2026
    Upstream:
    CVE-2020-11996
    Aliases:
    USN-4596-1

    Summary:

    Details: A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.

    References: https://ubuntu.com/security/CVE-2020-11996, https://www.openwall.com/lists/oss-security/2020/06/25/6, https://github.com/apache/tomcat/commit/9a0231683a77e2957cea0fdee88b193b30b0c976, https://github.com/apache/tomcat/commit/c8acd2ab7371e39aeca7c306f3b5380f00afe552, https://lists.apache.org/thread.html/r5541ef6b6b68b49f76fc4c45695940116da2bcbe0312ef204a00a2e0%40%3Cannounce.tomcat.apache.org%3E, https://lists.apache.org/thread.html/r74f5a8204efe574cbfcd95b2a16236fe95beb45c4d9fee3dc789dca9@%3Ccommits.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/r8f3d416c193bc9384a8a7dd368623d441f5fcaff1057115008100561@%3Ccommits.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/r8f7484589454638af527182ae55ef5b628ba00c05c5b11887c922fb1@%3Cnotifications.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/r93ca628ef3a4530dfe5ac49fddc795f0920a4b2a408b57a30926a42b@%3Ccommits.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/ra7092f7492569b39b04ec0decf52628ba86c51f15efb38f5853e2760@%3Cnotifications.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/rb4ee49ecc4c59620ffd5e66e84a17e526c2c3cfa95d0cd682d90d338@%3Cnotifications.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/rb820f1a2a02bf07414be12c653c2ab5321fd87b9bf6c5e635c53ff4b@%3Cnotifications.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/rc80b96b4b96618b2b7461cb90664a428cfd6605eea9f74e51b792542@%3Cnotifications.ofbiz.apache.org%3E, https://lists.apache.org/thread.html/rea65d6ef2e45dd1c45faae83922042732866c7b88fa109b76c83db52@%3Cnotifications.ofbiz.apache.org%3E, https://ubuntu.com/security/notices/USN-4596-1, https://www.cve.org/CVERecord?id=CVE-2020-11996

    Affected packages

    Package

    Name: tomcat8

    Purl: pkg:deb/ubuntu/tomcat8?arch=source&distro=esm-apps%2Fbionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    8.5.21-1ubuntu1
    8.5.29-1
    8.5.30-1
    8.5.30-1ubuntu1
    8.5.30-1ubuntu1.2
    8.5.30-1ubuntu1.3
    8.5.30-1ubuntu1.4
    8.5.39-1ubuntu1~18.04.1
    8.5.39-1ubuntu1~18.04.2
    8.5.39-1ubuntu1~18.04.3
    8.5.39-1ubuntu1~18.04.3+esm1
    8.5.39-1ubuntu1~18.04.3+esm2
    8.5.39-1ubuntu1~18.04.3+esm3
    8.5.39-1ubuntu1~18.04.3+esm4
    8.5.39-1ubuntu1~18.04.3+esm5
    8.5.39-1ubuntu1~18.04.3+esm6

    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-2020-11996 | CVE-DB