CVE-2021-4209A NULL pointer dereference flaw was found in GnuTLS.
Updated under an hour ago ()
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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 7 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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A NULL pointer dereference flaw was found in GnuTLS. As Nettle's hash update functions internally call memcpy, providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances.
- CVSS
- 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-476
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Modified
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 14, 2026
Affected products
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
gnu gnutls gnu:gnutls | before 3.7.3 | NVD |
redhat enterprise_linux redhat:enterprise_linux | 8.0 | NVD |
netapp active_iq_unified_manager netapp:active_iq_unified_manager | all versions | NVD |
netapp solidfire_&_hci_management_node netapp:solidfire_&_hci_management_node | all versions | NVD |
netapp hci_bootstrap_os netapp:hci_bootstrap_os | all versions | NVD |
References
- https://gitlab.com/gnutls/gnutls/-/issues/1306x-refsource-misc, third-party-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2044156x-refsource-misc, issue-tracking, third-party-advisory
- https://access.redhat.com/security/cve/CVE-2021-4209x-refsource-misc, third-party-advisory
- https://gitlab.com/gnutls/gnutls/-/merge_requests/1503x-refsource-misc, third-party-advisory
- https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568x-refsource-misc, patch, third-party-advisory
- https://security.netapp.com/advisory/ntap-20220915-0005/x-refsource-confirm, third-party-advisory
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.