CVE-2021-20305

Published: 05 April 2021

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.

Priority

Medium

CVSS 3 base score: 8.1

Status

Package Release Status
nettle
Launchpad, Ubuntu, Debian
Upstream
Released (3.7.2-1)
Ubuntu 21.04 (Hirsute Hippo)
Released (3.7-2.1ubuntu1)
Ubuntu 20.10 (Groovy Gorilla)
Released (3.6-2ubuntu0.1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (3.5.1+really3.5.1-2ubuntu0.1)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (3.4-1ubuntu0.1)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (3.2-1ubuntu0.16.04.2)
Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Patches:
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/a63893791280d441c713293491da97c79c0950fe
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/971bed6ab4b27014eb23085e8176917e1a096fd5
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/74ee0e82b6891e090f20723750faeb19064e31b2
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/51f643eee00e2caa65c8a2f5857f49acdf3ef1ce
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/401c8d53d8a8cf1e79980e62bda3f946f8e07c14
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/ae3801a0e5cce276c270973214385c86048d5f7b
Upstream: https://git.lysator.liu.se/nettle/nettle/-/commit/63f222c60b03470c0005aa9bc4296fbf585f68b9