Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2021-43527

9.8 · CRITICAL

NSS (Network Security Services) versions prior to 3.73 or 3.68.1 ESR are vulnerable to a heap overflow when handling DER-encoded DSA or RSA-PSS signatures.

Published Dec 8, 2021CWE-787EPSS 17.56%

Overview

CVE-2021-43527 is a critical-severity vulnerability. It was published on December 8, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).

This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical description

NSS (Network Security Services) versions prior to 3.73 or 3.68.1 ESR are vulnerable to a heap overflow when handling DER-encoded DSA or RSA-PSS signatures. Applications using NSS for handling signatures encoded within CMS, S/MIME, PKCS \#7, or PKCS \#12 are likely to be impacted. Applications using NSS for certificate validation or other TLS, X.509, OCSP or CRL functionality may be impacted, depending on how they configure NSS. *Note: This vulnerability does NOT impact Mozilla Firefox.* However, email clients and PDF viewers that use NSS for signature verification, such as Thunderbird, LibreOffice, Evolution and Evince are believed to be impacted. This vulnerability affects NSS < 3.73 and NSS < 3.68.1.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refbugzilla.mozilla.org/show_bug.cgi?id=1737470Refcert-portal.siemens.com/productcert/pdf/ssa-594438.pdfRefftp.mozilla.org/pub/security/nss/releases/NSS_3_68_1_RTM/Refftp.mozilla.org/pub/security/nss/releases/NSS_3_73_RTM/Refsecurity.gentoo.org/glsa/202212-05Refsecurity.netapp.com/advisory/ntap-20211229-0002/Refwww.mozilla.org/security/advisories/mfsa2021-51/Refwww.oracle.com/security-alerts/cpuapr2022.htmlRefwww.starwindsoftware.com/security/sw-20220802-0001/Refbugzilla.mozilla.org/show_bug.cgi?id=1737470

How CyberStrike helps

Frequently asked questions

What is CVE-2021-43527?

CVE-2021-43527 is a critical-severity vulnerability. It was published on December 8, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2021-43527?

This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-43527?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-43527?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-43527 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related CRITICAL CVEs from 2021

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999