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Fencer Intel
medium 5.9

CVE-2021-4160 json

BN_mod_exp may produce incorrect results on MIPS

published 4y ago modified 3mo ago also EUVD-2021-34028 , GHSA-ph2x-8239-7xc7 , JLSEC-2026-226

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.8%
EPSS 3.8% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

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).

Patch / fix

  • julia OpenSSL_jll 1.1.13+0
  • julia Openresty_jll 1.21.4+0
  • openssl openssl 1.1.1m
  • siemens sinec_ins 1.0
  • openssl Debian 14, Debian 13, Debian 12 1.1.1m-1

debian advisories DEBIAN-CVE-2021-4160

  • openssl CBL-Mariner 2.0 1.1.1k-13

azure linux advisories AZL-8472

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-4160 updated cvss 5.9

openssl: Carry propagation bug in the MIPS32 and MIPS64 squaring procedure

  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/management-ingress-rhel8 Red Hat Enterprise Linux 6 openssl, openssl098e, openssl-perl Red Hat Enterprise Linux 7 openssl, openssl098e, openssl-libs, openssl-perl Red Hat Enterprise Linux 8 openssl, openssl-libs, openssl-perl, compat-openssl10 Red Hat Enterprise Linux 9 openssl, openssl-libs, openssl-perl Red Hat JBoss Core Services jbcs-httpd24-openssl
    +2 more products
    Red Hat JBoss Web Server 3 openssl Red Hat JBoss Web Server 5 openssl
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

3.77% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia OpenSSL_jll
<1.1.13+0
1.1.13+0
julia Openresty_jll
<1.21.4+0
1.21.4+0

Affected products

  • OpenSSL OpenSSL

Classification

Technology feeds

References

Sources

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