NSS (Network Security Services) is a set of libraries that supports cross-platform development of secure client and server applications. It provides server-side hardware TLS/SSL acceleration and optional support for client-side smart cards.
On December 1, 2021, Mozilla had issued a risk notice for Mozilla Network Security Services buffer heap overflow, the vulnerability number is CVE-2021-43527, the vulnerability level is critical. This vulnerability does not affect Mozilla Firefox. However, email clients and PDF viewers that use NSS for signature verification, such as Thunderbird, LibreOffice, Evolution, and Evince, are affected.
Vulnerability Detail
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.
In this regard, we recommend that users upgrade Mozilla NSS to the latest version in time. “This is a major memory corruption flaw in NSS, almost any use of NSS is affected,” Tavis Ormandy of Google Project Zero tweeted. “If you are a vendor that distributes NSS in your products, you will most likely need to update or backport the patch.”
