UBUNTU-CVE-2021-33913

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    UBUNTU-CVE-2021-33913

    Published: 19 Jan 2022Last Modified: 22 Apr 2026
    Upstream:
    CVE-2021-33913

    Summary:

    Details: libspf2 before 1.2.11 has a heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of SPF_record_expand_data in spf_expand.c. The amount of overflowed data depends on the relationship between the length of an entire domain name and the length of its leftmost label. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.

    References: https://ubuntu.com/security/CVE-2021-33913, https://github.com/shevek/libspf2/commit/f06fef6cede4c4cb42f2c617496e6041782d7070, https://ubuntu.com/security/notices/USN-6584-1, https://ubuntu.com/security/notices/USN-6584-2, https://www.cve.org/CVERecord?id=CVE-2021-33913

    Affected packages

    Package

    Name: libspf2

    Purl: pkg:deb/ubuntu/[email protected]~esm2?arch=source&distro=esm-apps/xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1.2.10-6ubuntu0.1~esm2

    Affected versions

    1.2.10-6
    1.2.10-6build1
    1.2.10-6ubuntu0.1~esm1

    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-2021-33913 | CVE-DB