Mozilla Foundation Security Advisory 2021-51

Memory corruption in NSS via DER-encoded DSA and RSA-PSS signatures

Announced
December 1, 2021
Impact
critical
Products
NSS
Fixed in
  • NSS 3.68.1
  • NSS 3.73

#CVE-2021-43527: Memory corruption via DER-encoded DSA and RSA-PSS signatures

Reporter
Tavis Ormandy of Google Project Zero
Impact
critical
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.

References