UBUNTU-CVE-2021-34813

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    UBUNTU-CVE-2021-34813

    Published: 16 Jun 2021Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-34813
    Aliases:
    USN-5194-1

    Summary:

    Details: Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.

    References: https://ubuntu.com/security/CVE-2021-34813, https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b, https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3, https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm, https://ubuntu.com/security/notices/USN-5194-1, https://www.cve.org/CVERecord?id=CVE-2021-34813

    Affected packages

    Package

    Name: olm

    Purl: pkg:deb/ubuntu/[email protected]+dfsg-2ubuntu0.1~esm1?arch=source&distro=esm-apps/focal

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -3.1.3+dfsg-2ubuntu0.1~esm1

    Affected versions

    3.1.3+dfsg-2
    3.1.3+dfsg-2build1
    3.1.3+dfsg-2build2

    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-2021-34813 | CVE-DB