Debian DSA-5103-1 : openssl - security update

medium Nessus Plugin ID 158979


The remote Debian host is missing one or more security-related updates.


The remote Debian 10 / 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5103 advisory.

- There is a carry propagation bug in the MIPS32 and MIPS64 squaring procedure. Many EC algorithms are affected, including some of the TLS 1.3 default curves. Impact was not analyzed in detail, because the pre-requisites for attack are considered unlikely and include reusing private keys. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be significant. However, for an attack on TLS to be meaningful, the server would have to share the DH private key among multiple clients, which is no longer an option since CVE-2016-0701. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0.0. It was addressed in the releases of 1.1.1m and 3.0.1 on the 15th of December 2021. For the 1.0.2 release it is addressed in git commit 6fc1aaaf3 that is available to premium support customers only. It will be made available in 1.0.2zc when it is released. The issue only affects OpenSSL on MIPS platforms. Fixed in OpenSSL 3.0.1 (Affected 3.0.0). Fixed in OpenSSL 1.1.1m (Affected 1.1.1-1.1.1l). Fixed in OpenSSL 1.0.2zc- dev (Affected 1.0.2-1.0.2zb). (CVE-2021-4160)

- The BN_mod_sqrt() function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature, any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self- signed certificate to trigger the loop during verification of the certificate signature. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0. It was addressed in the releases of 1.1.1n and 3.0.2 on the 15th March 2022. Fixed in OpenSSL 3.0.2 (Affected 3.0.0,3.0.1). Fixed in OpenSSL 1.1.1n (Affected 1.1.1-1.1.1m). Fixed in OpenSSL 1.0.2zd (Affected 1.0.2-1.0.2zc). (CVE-2022-0778)

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


Upgrade the openssl packages.

For the stable distribution (bullseye), this problem has been fixed in version 1.1.1k-1+deb11u2.

See Also

Plugin Details

Severity: Medium

ID: 158979

File Name: debian_DSA-5103.nasl

Version: 1.3

Type: local

Agent: unix

Published: 3/16/2022

Updated: 6/3/2022

Supported Sensors: Frictionless Assessment Agent, Nessus Agent

Risk Information


Risk Factor: High

Score: 7.1


Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.4

Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N

Temporal Vector: E:POC/RL:OF/RC:C

CVSS Score Source: CVE-2021-4160


Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.3

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:libcrypto1.1-udeb, p-cpe:/a:debian:debian_linux:libssl-dev, p-cpe:/a:debian:debian_linux:libssl-doc, p-cpe:/a:debian:debian_linux:libssl1.1, p-cpe:/a:debian:debian_linux:libssl1.1-udeb, p-cpe:/a:debian:debian_linux:openssl, cpe:/o:debian:debian_linux:10.0, cpe:/o:debian:debian_linux:11.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/15/2022

Vulnerability Publication Date: 12/30/2021

Reference Information

CVE: CVE-2021-4160, CVE-2022-0778

IAVA: 2021-A-0602