Buffer overflow in Mozilla Nss
CVE-2021-43527
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.
Vulnerability class: Buffer Overflow
EPSS: 0.176 (96.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Mozilla Nss — versions unspecified
- Mozilla Nss_esr
- Netapp Cloud_backup
- Netapp E-series_santricity_os_controller
- Oracle Communications_cloud_native_core_binding_support_function — versions 1.11.0
- Oracle Communications_cloud_native_core_network_repository_function — versions 1.15.0, 1.15.1
- Oracle Communications_cloud_native_core_network_slice_selection_function — versions 1.8.0
- Oracle Communications_policy_management — versions 12.6.0.0.0
- Starwindsoftware Starwind_san_\&_nas — versions v8r13
- Starwindsoftware Starwind_virtual_san — versions v8r13
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Permissions Required, Issue Tracking, Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Patch, Third Party Advisory)
- security@mozilla.org (Third Party Advisory)
- security@mozilla.org (Third Party Advisory)
- security@mozilla.org (Third Party Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-43527?
- CVE-2021-43527 is a critical-severity vulnerability in Mozilla Nss, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2021-12-08.
- How severe is CVE-2021-43527?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2021-43527 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.