How severe is CVE-2020-12607?

CVE-2020-12607 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-12607 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-12607?

CVE-2020-12607 affects Antonkueltz Fastecdsa. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-12607?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-12607 published?

CVE-2020-12607 was published on 2020-06-02 and last updated on 2026-06-17.

CVE-2020-12607

CVE-2020-12607 is a high-severity vulnerability in Antonkueltz Fastecdsa with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Antonkueltz Fastecdsa
Published: 2020-06-02
Last modified: 2026-06-17

Description

An issue was discovered in fastecdsa before 2.1.2. When using the NIST P-256 curve in the ECDSA implementation, the point at infinity is mishandled. This means that for an extreme value in k and s^-1, the signature verification fails even if the signature is correct. This behavior is not solely a usability problem. There are some threat models where an attacker can benefit by successfully guessing users for whom signature verification will fail.

Frequently asked questions

What is CVE-2020-12607?: An issue was discovered in fastecdsa before 2.1.2. When using the NIST P-256 curve in the ECDSA implementation, the point at infinity is mishandled. This means that for an extreme value in k and s^-1, the signature verification fails even if the signature is correct. This behavior is not solely a usability problem. There are some threat models where an attacker can benefit by successfully guessing users for whom signature verification will fail.
How severe is CVE-2020-12607?: CVE-2020-12607 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-12607 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-12607?: CVE-2020-12607 affects Antonkueltz Fastecdsa. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-12607?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-12607 published?: CVE-2020-12607 was published on 2020-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:antonkueltz:fastecdsa:*:*:*:*:*:*:*:*

More vulnerabilities in Antonkueltz Fastecdsa

CVE-2024-21502 — High (CVSS 7.5): Versions of the package fastecdsa before 2.3.2 are vulnerable to Use of Uninitialized Variable on the stack, via the…

All CVEs affecting Antonkueltz Fastecdsa →

Other CWE-347 (Improper Verification of Cryptographic Signature) vulnerabilities

CVE-2026-48558 — Critical (CVSS 10.0): SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the…
CVE-2023-25574 — Critical (CVSS 10.0): `jupyterhub-ltiauthenticator` is a JupyterHub authenticator for learning tools interoperability (LTI).…
CVE-2024-45409 — Critical (CVSS 10.0): The Ruby SAML library is for implementing the client side of a SAML authorization. Ruby-SAML in <= 12.2 and 1.13.0 <=…
CVE-2024-32962 — Critical (CVSS 10.0): xml-crypto is an xml digital signature and encryption library for Node.js. In affected versions the default…
CVE-2022-24884 — Critical (CVSS 10.0): ecdsautils is a tiny collection of programs used for ECDSA (keygen, sign, verify). `ecdsa_verify_[prepare_]legacy()`…
CVE-2021-33885 — Critical (CVSS 10.0): An Insufficient Verification of Data Authenticity vulnerability in B. Braun SpaceCom2 prior to 012U000062 allows a…

Browse all CWE-347 (Improper Verification of Cryptographic Signature) vulnerabilities →