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 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.

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.

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.

Nettle is a cryptographic library designed to fit any context: in crypto toolkits for object-oriented languages, in applications like LSH or GnuPG, or even in kernel space.

Security Fix(es):

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.(CVE-2021-20305)

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

Nettle is a cryptographic library that is designed to fit easily in almost any context: In crypto toolkits for object-oriented languages, such as C++, Python, or Pike, in applications like LSH or GNUPG, or even in kernel space.

Security Fix(es):

• nettle: Out of bounds memory access in signature verification (CVE-2021-20305)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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.

Remote crash in RSA decryption via manipulated ciphertext (CVE-2021-3580).

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 (CVE-2021-20305).

The Mageia 8 nettle package has been updated to version 3.7.3 and the Mageia 7 nettle package has been patched to fix these issues.

This update for libnettle fixes the following issues:

• CVE-2021-20305: Fixed the multiply function which was being called with out-of-range scalars (bsc#1184401).

This update was imported from the SUSE:SLE-15:Update update project.

These are all security issues fixed in the libhogweed6-3.7.3-1.2 package on the GA media of openSUSE Tumbleweed.

This update for libnettle fixes the following issues:

• CVE-2021-20305: Fixed the multiply function which was being called with out-of-range scalars (bsc#1184401, bsc#1183835).

This update for libnettle fixes the following issues:

• CVE-2021-20305: Fixed the multiply function which was being called with out-of-range scalars (bsc#1184401).

It was discovered that Nettle incorrectly handled signature verification. A remote attacker could use this issue to cause Nettle to crash, resulting in a denial of service, or possibly force invalid signatures.