CVE-2021-4160

medium

Description

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).

References

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=6fc1aaaf303185aa5e483e06bdfae16daa9193a7

https://www.openssl.org/news/secadv/20220128.txt

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=3bf7b73ea7123045b8f972badc67ed6878e6c37f

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=e9e726506cd2a3fd9c0f12daf8cc1fe934c7dddb

https://www.debian.org/security/2022/dsa-5103

https://www.oracle.com/security-alerts/cpuapr2022.html

https://www.oracle.com/security-alerts/cpujul2022.html

Details

Source: MITRE

Published: 2022-01-28

Updated: 2022-07-25

Risk Information

CVSS v2

Base Score: 4.3

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

Impact Score: 2.9

Exploitability Score: 8.6

Severity: MEDIUM

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Impact Score: 3.6

Exploitability Score: 2.2

Severity: MEDIUM