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TI-2021-03594 Aliases CVE-2021-20305GHSA-6xrq-2ww3-f6h5

Broken or risky cryptographic algorithm in nettle

Priority LOW 39CWE-327Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Information disclosure, Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-327, CWE-787 and the CVSS impact.

Summary

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.

Why it matters now

EPSS 0.01742 77th percentileScored 2026-11-07
Fix Fixed Red Hat: 8 advisories

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—nettlenettle 3.7.2—No fix listedCNA
  • nettle Vendor— Affected nettle 3.7.2 Fixed in — No fix listed CNA

CPE configurations NVD · 8

CPEVersionsRoleVendor
cpe:2.3:a:nettle_project:nettle:*:*:*:*:*:*:*:*before 3.7.2VulnerableNettle Project
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
  • cpe:2.3:a:nettle_project:nettle:*:*:*:*:*:*:*:* Versions before 3.7.2 Vulnerable ·Nettle Project
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
  • cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian

Remediation

Red Hat 8 advisories

  • RHSA-2021:2760 Released 2021-07-19 · Red Hat rating Important
    nettle security update
    • Red Hat Enterprise Linux Server AUS (v. 7.3) nettle-2.7.1-9.el7_3, nettle-devel-2.7.1-9.el7_3
  • RHSA-2021:2758 Released 2021-07-15 · Red Hat rating Important
    nettle security update
    • Red Hat Enterprise Linux Server AUS (v. 7.4) nettle-2.7.1-9.el7_4, nettle-devel-2.7.1-9.el7_4
    • Red Hat Enterprise Linux Server E4S (v. 7.4) nettle-2.7.1-9.el7_4, nettle-devel-2.7.1-9.el7_4
    • Red Hat Enterprise Linux Server TUS (v. 7.4) nettle-2.7.1-9.el7_4, nettle-devel-2.7.1-9.el7_4
  • RHSA-2021:2356 Released 2021-06-09 · Red Hat rating Important
    nettle security update
    • Red Hat Enterprise Linux Server AUS (v. 7.6) nettle-2.7.1-9.el7_6, nettle-devel-2.7.1-9.el7_6
    • Red Hat Enterprise Linux Server E4S (v. 7.6) nettle-2.7.1-9.el7_6, nettle-devel-2.7.1-9.el7_6
    • Red Hat Enterprise Linux Server TUS (v. 7.6) nettle-2.7.1-9.el7_6, nettle-devel-2.7.1-9.el7_6
Show 5 more Red Hat advisories
  • RHSA-2021:2280 Released 2021-06-07 · Red Hat rating Important
    nettle security update
    • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) nettle-2.7.1-9.el7_7
    • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) nettle-devel-2.7.1-9.el7_7
    • Red Hat Enterprise Linux Server EUS (v. 7.7) nettle-2.7.1-9.el7_7, nettle-2.7.1-9.el7_7.ppc, nettle-devel-2.7.1-9.el7_7 +1
  • RHSA-2021:1246 Released 2021-04-19 · Red Hat rating Important
    gnutls and nettle security update
    • Red Hat Enterprise Linux AppStream EUS (v. 8.2) gnutls-c++-3.6.8-12.el8_2, gnutls-dane-3.6.8-12.el8_2, gnutls-devel-3.6.8-12.el8_2 +2
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) gnutls-3.6.8-12.el8_2, nettle-3.4.1-2.el8_2
  • RHSA-2021:1245 Released 2021-04-19 · Red Hat rating Important
    gnutls and nettle security update
    • Red Hat Enterprise Linux AppStream EUS (v. 8.1) gnutls-c++-3.6.8-10.el8_1, gnutls-dane-3.6.8-10.el8_1, gnutls-devel-3.6.8-10.el8_1 +2
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) gnutls-3.6.8-10.el8_1, nettle-3.4.1-2.el8_1
  • RHSA-2021:1206 Released 2021-04-14 · Red Hat rating Important
    gnutls and nettle security update
    • Red Hat Enterprise Linux AppStream (v. 8) gnutls-c++-3.6.14-8.el8_3, gnutls-dane-3.6.14-8.el8_3, gnutls-devel-3.6.14-8.el8_3 +2
    • Red Hat Enterprise Linux BaseOS (v. 8) gnutls-3.6.14-8.el8_3, nettle-3.4.1-4.el8_3
  • RHSA-2021:1145 Released 2021-04-08 · Red Hat rating Important
    nettle security update
    • Red Hat Enterprise Linux Client (v. 7) nettle-2.7.1-9.el7_9
    • Red Hat Enterprise Linux Client Optional (v. 7) nettle-devel-2.7.1-9.el7_9
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) nettle-devel-2.7.1-9.el7_9
    • Red Hat Enterprise Linux Server (v. 7) nettle-2.7.1-9.el7_9, nettle-2.7.1-9.el7_9.ppc, nettle-devel-2.7.1-9.el7_9 +1
    • Red Hat Enterprise Linux Workstation (v. 7) nettle-2.7.1-9.el7_9, nettle-devel-2.7.1-9.el7_9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:1206
Red Hat Enterprise Linux AppStream EUS (v. 8.1)Fixed RHSA-2021:1245
Red Hat Enterprise Linux AppStream EUS (v. 8.2)Fixed RHSA-2021:1246
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:1206
Red Hat Enterprise Linux BaseOS EUS (v. 8.1)Fixed RHSA-2021:1245
Red Hat Enterprise Linux BaseOS EUS (v. 8.2)Fixed RHSA-2021:1246
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2021:1145
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2021:1145
Red Hat Enterprise Linux ComputeNode EUS (v. 7.7)Fixed RHSA-2021:2280
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2021:1145
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7)Fixed RHSA-2021:2280
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:1145
Red Hat Enterprise Linux Server AUS (v. 7.3)Fixed RHSA-2021:2760
Red Hat Enterprise Linux Server AUS (v. 7.4)Fixed RHSA-2021:2758
Red Hat Enterprise Linux Server AUS (v. 7.6)Fixed RHSA-2021:2356
Red Hat Enterprise Linux Server E4S (v. 7.4)Fixed RHSA-2021:2758
Red Hat Enterprise Linux Server E4S (v. 7.6)Fixed RHSA-2021:2356
Red Hat Enterprise Linux Server EUS (v. 7.7)Fixed RHSA-2021:2280
Red Hat Enterprise Linux Server TUS (v. 7.4)Fixed RHSA-2021:2758
Red Hat Enterprise Linux Server TUS (v. 7.6)Fixed RHSA-2021:2356
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:1145
Not affected: 4 products
  • Red Hat Enterprise Linux 9
  • Red Hat OpenStack Platform 10 (Newton)
  • Red Hat OpenStack Platform 13 (Queens)
  • Red Hat OpenStack Platform 16.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-20305
  2. 2026-10-03 Alias added: GHSA-6xrq-2ww3-f6h5

References

Patch 1

Advisory 5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences