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Findings

CVE-2021-20305

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 Crypt…

Published Apr 5, 2021 · updated Oct 14, 2026 · nettle project nettle

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.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 5, 2021 · NIST NVD

    Detected

    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. T

  2. Oct 14, 2026 · NIST NVD

    Updated

    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. T

Affected

  • cpe debian/debian linux10.0
  • cpe debian/debian linux9.0
  • cpe fedoraproject/fedora33
  • cpe netapp/active iq unified managerversion unspecified
  • cpe netapp/ontap select deploy administration utilityversion unspecified
  • cpe nettle project/nettleversion unspecified
  • cpe redhat/enterprise linux7.0
  • cpe redhat/enterprise linux8.0

Sources

  • CVE.orgCVE-2021-20305

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2021-20305

    30-day exploitation probability 1.7%

    first.org
  • NIST NVDCVE-2021-20305

    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 res

    nvd.nist.gov

References