CVE-2021-20305

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    CVE-2021-20305

    Published: 5 Apr 2021Last Modified: 16 Apr 2026

    Summary:

    Details: A flaw was found in Nettle in versions before 3.7.2, where several Nettle signature verification functions (GOST DSA, EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being called with out-of-range scalers, possibly resulting in incorrect results. This flaw allows an attacker to force an invalid signature, causing an assertion failure or possible validation. The highest threat to this vulnerability is to confidentiality, integrity, as well as system availability.

    References: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MQKWVVMAIDAJ7YAA3VVO32BHLDOH2E63/, https://security.gentoo.org/glsa/202105-31, https://security.netapp.com/advisory/ntap-20211022-0002/, https://www.debian.org/security/2021/dsa-4933, https://lists.debian.org/debian-lts-announce/2021/09/msg00008.html, https://bugzilla.redhat.com/show_bug.cgi?id=1942533

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    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-2021-20305 | CVE-DB