CVE-2021-3449 — NULL pointer deref in signature_algorithms processing
An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 63.5% (30-day exploitation probability)+15
- Technical severity (medium)+3
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — cert-portal.siemens.com (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Checkpoint Multi-domain Management Firmware, Checkpoint Quantum Security Gateway Firmware, Checkpoint Quantum Security Management Firmware…).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Checkpoint | Multi-domain Management Firmware | version r80.40version r81 | Vulnerable | NIST National Vulnerability Database |
| Checkpoint | Quantum Security Gateway Firmware | version r80.40version r81 | Vulnerable | NIST National Vulnerability Database |
| Checkpoint | Quantum Security Management Firmware | version r80.40version r81 | Vulnerable | NIST National Vulnerability Database |
| Debian | Debian Linux | version 9.0version 10.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 34 | Vulnerable | NIST National Vulnerability Database |
| Freebsd | Freebsd | version 12.2version 12.2-p1version 12.2-p2 | Vulnerable | NIST National Vulnerability Database |
| Mcafee | Web Gateway | version 8.2.19version 9.2.10version 10.1.1 | Vulnerable | NIST National Vulnerability Database |
| Mcafee | Web Gateway Cloud Service | version 8.2.19version 9.2.10version 10.1.1 | Vulnerable | NIST National Vulnerability Database |
| Netapp | Active Iq Unified Manager | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Cloud Volumes Ontap Mediator | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | E-series Performance Analyzer | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Oncommand Insight | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Oncommand Workflow Automation | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Ontap Select Deploy Administration Utility | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Santricity Smi-s Provider | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Snapcenter | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Storagegrid | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Nodejs | Node.js | ≥ 10.0.0 and ≤ 10.12.0≥ 10.13.0 and ≤ 10.24.0≥ 12.0.0 and ≤ 12.12.0≥ 12.13.0 and < 12.22.1≥ 14.0.0 and ≤ 14.14.0≥ 14.15.0 and < 14.16.1≥ 15.0.0 and < 15.14.0 | Vulnerable | NIST National Vulnerability Database |
| Openssl | Openssl | ≥ 1.1.1 and < 1.1.1k | Vulnerable | NIST National Vulnerability Database |
| Openssl | Openssl | version Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j) | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Oracle | Communications Communications Policy Management | version 12.6.0.0.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Enterprise Manager For Storage Management | version 13.4.0.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Essbase | version 21.2 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Graalvm | version 19.3.5version 20.3.1.2version 21.0.0.2 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Jd Edwards Enterpriseone Tools | < 9.2.6.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Jd Edwards World Security | version a9.4 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Mysql Connectors | ≤ 8.0.23 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Mysql Server | ≤ 5.7.33≥ 8.0.15 and ≤ 8.0.23 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Mysql Workbench | ≤ 8.0.23 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Peoplesoft Enterprise Peopletools | version 8.57version 8.58version 8.59 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Primavera Unifier | ≥ 17.7 and ≤ 17.12version 19.12version 20.12version 21.12 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Secure Backup | < 18.1.0.1.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Secure Global Desktop | version 5.6 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Zfs Storage Appliance Kit | version 8.8 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Ruggedcom Rcm1224 Firmware | ≥ 6.2 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Lpe9403 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance M-800 Firmware | ≥ 6.2 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance S602 Firmware | ≥ 4.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance S612 Firmware | ≥ 4.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance S615 Firmware | ≥ 6.2 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance S623 Firmware | ≥ 4.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance S627-2m Firmware | ≥ 4.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Sc-600 Firmware | ≥ 2.0 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance W1700 Firmware | ≥ 2.0 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance W700 Firmware | ≥ 6.5 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xb-200 Firmware | < 4.3 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xc-200 Firmware | < 4.3 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xf-200ba Firmware | < 4.3 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xm-400 Firmware | < 6.4 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xp-200 Firmware | < 4.3 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xr-300wg Firmware | < 4.3 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xr524-8c Firmware | < 6.4 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xr526-8c Firmware | < 6.4 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xr528-6m Firmware | < 6.4 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Scalance Xr552-12 Firmware | < 6.4 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Cloud Connect 7 Firmware | ≥ 1.1versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Cp 1242-7 Gprs V2 Firmware | ≥ 3.1versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Hmi Basic Panels 2nd Generation Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Hmi Comfort Outdoor Panels Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Hmi Ktp Mobile Panels Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Logon | version 1.5-sp3_update_1≥ 1.6.0.2 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Mv500 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1243-1 Firmware | ≥ 3.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1243-8 Irc Firmware | ≥ 3.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1542sp-1 Irc Firmware | ≥ 2.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1543-1 Firmware | ≥ 2.2 and < 3.0 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1543sp-1 Firmware | ≥ 2.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp 1545-1 Firmware | ≥ 1.0 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp1243-7 Lte Eu Firmware | ≥ 3.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Net Cp1243-7 Lte Us Firmware | ≥ 3.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Pcs 7 Telecontrol Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Pcs Neo Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Pdm Firmware | ≥ 9.1.0.7 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Process Historian Opc Ua Server Firmware | ≥ 2019 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf166c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf185c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf186c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf186ci Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf188c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf188ci Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Rf360r Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1211c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1212c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1212fc Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1214 Fc Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1214c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1215 Fc Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1215c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1200 Cpu 1217c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic S7-1500 Cpu 1518-4 Pn/dp Mfp Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Wincc Runtime Advanced | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Simatic Wincc Telecontrol | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinamics Connect 300 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinec Infrastructure Network Services | < 1.0.1.1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinec Nms | version 1.0version 1.0-sp1 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinec Pni | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinema Server | version 14.0version 14.0-sp1version 14.0-sp2version 14.0-sp2_update1version 14.0-sp2_update2 | Vulnerable | NIST National Vulnerability Database |
| Siemens | Sinumerik Opc Ua Server | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Tia Administrator | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Siemens | Tim 1531 Irc Firmware | ≥ 2.0 and < 2.2 | Vulnerable | NIST National Vulnerability Database |
| Sonicwall | Capture Client | version 3.5 | Vulnerable | NIST National Vulnerability Database |
| Sonicwall | Sma 100 Firmware | ≥ 10.2.0.0 and < 10.2.1.0-17sv | Vulnerable | NIST National Vulnerability Database |
| Sonicwall | Sonicos | version 7.0.1.0 | Vulnerable | NIST National Vulnerability Database |
| Tenable | Log Correlation Engine | < 6.0.9 | Vulnerable | NIST National Vulnerability Database |
| Tenable | Nessus | ≤ 8.13.1 | Vulnerable | NIST National Vulnerability Database |
| Tenable | Nessus Network Monitor | version 5.11.0version 5.11.1version 5.12.0version 5.12.1version 5.13.0 | Vulnerable | NIST National Vulnerability Database |
| Tenable | Tenable.sc | ≥ 5.13.0 and ≤ 5.17.0 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.9 | CVSS 3.1 | Medium | 2.2 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 4.3 | CVSS 2.0 | Medium | 8.6 | 2.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 63.54%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · openssl/openssl
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.9
- Source status changed · → Modified
- Record created in this database
- 2021
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
29 on the record
- www.openssl.org/news/secadv/20210325.txt
- cert-portal.siemens.com/productcert/pdf/ssa-772220.pdf
- www.oracle.com/security-alerts/cpuapr2022.html
- www.oracle.com/security-alerts/cpuApr2021.html
- www.oracle.com//security-alerts/cpujul2021.html
- security.netapp.com/advisory/ntap-20240621-0006/
- security.gentoo.org/glsa/202103-03
- www.openwall.com/lists/oss-security/2021/03/28/4
- www.tenable.com/security/tns-2021-09
- www.oracle.com/security-alerts/cpuoct2021.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CCBF
- security.FreeBSD.org/advisories/FreeBSD-SA-21:07.openssl.asc
- cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
- lists.debian.org/debian-lts-announce/2021/08/msg00029.html
- kc.mcafee.com/corporate/index
- security.netapp.com/advisory/ntap-20210513-0002/
- www.openwall.com/lists/oss-security/2021/03/28/3
- www.tenable.com/security/tns-2021-06
- security.netapp.com/advisory/ntap-20210326-0006/
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-openssl-2021-G
- www.debian.org/security/2021/dsa-4875
- kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44845
- www.oracle.com/security-alerts/cpujul2022.html
- www.tenable.com/security/tns-2021-10
- www.openwall.com/lists/oss-security/2021/03/27/1
- www.tenable.com/security/tns-2021-05
- www.openwall.com/lists/oss-security/2021/03/27/2
- git.openssl.org/gitweb/
- psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0013
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-84784 QUIC: Unbounded RETIRE_CONNECTION_ID Backlog 16d
- High CVE-2026-84782 DTLS Retransmits Handshake Messages From a Stale Buffer Offset 16d
- High CVE-2026-84783 Use-After-Free in X.509 Extension Cache Under Concurrent Use 16d
- Low CVE-2026-77696 Timing Side-Channel in SM2 Signature Generation 16d
- Medium CVE-2026-75805 NULL Pointer Dereference in CMP Client Revocation Response Handling 16d
- Medium CVE-2026-75806 Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS 16d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-3449 is "NULL pointer deref in signature_algorithms processing", rated Medium. It affects Multi-domain Management Firmware (Checkpoint); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.9 describes technical severity. EPSS 63.54% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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