CVE-2021-39921

    Dashboard / Vulnerabilities / CVE-2021-39921

    CVE-2021-39921

    Published: 19 Nov 2021Last Modified: 8 Jul 2026

    Summary:

    Details: NULL pointer exception in the Modbus dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

    References: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A6AJFIYIHS3TYDD2EBYBJ5KKE52X34BJ/, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YEWTIRMC2MFQBZ2O5M4CJHJM4JPBHLXH/, https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39921.json, https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html, https://security.gentoo.org/glsa/202210-04, https://www.debian.org/security/2021/dsa-5019, https://www.wireshark.org/security/wnpa-sec-2021-14.html, https://gitlab.com/wireshark/wireshark/-/issues/17703

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- e0ed4cfa3d72110257da54c26ad3a28d282ef454
    Fixed -None

    Affected versions

    wireshark-3.2.17
    wireshark-3.2.16
    wireshark-3.2.15
    wireshark-3.2.14
    wireshark-3.2.13
    wireshark-3.2.12
    wireshark-3.2.11
    wireshark-3.2.10
    wireshark-3.2.9
    wireshark-3.2.8
    wireshark-3.2.7
    wireshark-3.2.6
    wireshark-3.2.5
    wireshark-3.2.4
    wireshark-3.2.3
    wireshark-3.2.2
    wireshark-3.2.1
    wireshark-3.2.0

    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
    CVE-2021-39921 | CVE-DB