CVE-2021-43527

high-risk
Published 2021-12-08

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.

Do I need to act?

~
5.2% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (11)

Nss
Nss Esr
Starwind San \& Nas

Affected Vendors

Oracle Mozilla Netapp Starwindsoftware

References (18)

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1737470
Third Party Advisory https://cert-portal.siemens.com/productcert/pdf/ssa-594438.pdf
Vendor Advisory https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_68_1_RTM/
Vendor Advisory https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_73_RTM/
Third Party Advisory https://security.gentoo.org/glsa/202212-05
Third Party Advisory https://security.netapp.com/advisory/ntap-20211229-0002/
Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-51/
Patch https://www.oracle.com/security-alerts/cpuapr2022.html
Third Party Advisory https://www.starwindsoftware.com/security/sw-20220802-0001/
Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1737470
Third Party Advisory https://cert-portal.siemens.com/productcert/pdf/ssa-594438.pdf
Vendor Advisory https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_68_1_RTM/
Vendor Advisory https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_73_RTM/
Third Party Advisory https://security.gentoo.org/glsa/202212-05
Third Party Advisory https://security.netapp.com/advisory/ntap-20211229-0002/
Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-51/
Patch https://www.oracle.com/security-alerts/cpuapr2022.html
Third Party Advisory https://www.starwindsoftware.com/security/sw-20220802-0001/
56
/ 100
high-risk
Severity 32/34 · Critical
Exploitability 8/34 · Low
Exposure 16/34 · Moderate