The ECDSA signature implementation in ecdsa.c in Arm Mbed Crypto 2.1 and Mbed TLS through 2.19.1 does not reduce the blinded scalar before computing the inverse, which allows a local attacker to recover the private key via side-channel attacks.

The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3249 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3249-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Markus Koschany     December 26, 2022                             https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : mbedtls     Version        : 2.16.9-0~deb10u1     CVE ID         : CVE-2019-16910 CVE-2019-18222 CVE-2020-10932 CVE-2020-10941                      CVE-2020-16150 CVE-2020-36421 CVE-2020-36422 CVE-2020-36423                      CVE-2020-36424 CVE-2020-36425 CVE-2020-36426 CVE-2020-36475                      CVE-2020-36476 CVE-2020-36478 CVE-2021-24119 CVE-2021-43666                      CVE-2021-44732 CVE-2022-35409     Debian Bug     : 941265 963159 972806 1002631

    Multiple security vulnerabilities have been discovered in mbedtls, a     lightweight crypto and SSL/TLS library, which may allow attackers to obtain     sensitive information like the RSA private key or cause a denial of service     (application or server crash).

    For Debian 10 buster, these problems have been fixed in version     2.16.9-0~deb10u1.

    We recommend that you upgrade your mbedtls packages.

    For the detailed security status of mbedtls please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/mbedtls

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: This is a digitally signed message part

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Janos Follath reports :

Our bignum implementation is not constant time/constant trace, so side channel attacks can retrieve the blinded value, factor it (as it is smaller than RSA keys and not guaranteed to have only large prime factors), and then, by brute force, recover the key.

- Update to 2.16.4

  - CVE-2019-18222

Release notes:
https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.4-and-2.7.13-r eleased

Security Advisory:
https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security
-advisory-2019-12

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
169300	Debian dla-3249 : libmbedcrypto3 - security update	Nessus	Debian Local Security Checks	critical
133972	FreeBSD : Mbed TLS -- Side channel attack on ECDSA (b70b880f-5727-11ea-a2f3-001cc0382b2f)	Nessus	FreeBSD Local Security Checks	medium
133778	Fedora 30 : mbedtls (2020-8d3ea0fe8d)	Nessus	Fedora Local Security Checks	medium
133776	Fedora 31 : mbedtls (2020-5bcfae9f46)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2019-18222

medium

Tenable Plugins

critical

medium

medium

medium