CVE-2021-3449

mediumpriority · attend · 56EPSS 0.635 · 99 %ileexploit · PoCDEEURUUS
grimoire priorityP1 · Urgent
Exploitable?
Public exploit
1 exploit · PoC
Likely / severe?
63.5% (99th) EPSS
CVSS 4.3 · medium
Is it mine?
316 products
Check your exposure
Who says so?
9 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-22

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).

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

7.4
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.4

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 2.9
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 3.6
v3.05.9mediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · CISA US
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · Phoenix Contact PSIRT DE
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Hsecondary · CVSS-BT (t0sche)
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · CISA US
v3.15.9mediumAV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-476USprimaryCWE-476USCWE-476USCWE-476USCWE-476USCWE-476US
04

exploits (1)

Public proof-of-concept and weaponised exploit code.

05

affected products (316)

Products and version ranges known to be affected.

showing 20 of 316
06

advisories (15)

Vendor and ecosystem advisories describing this.

  • SSA-389290SSA-389290: Third-Party Component Vulnerabilities in SINEC INS2022-03-08csaf · siemens_psirtDE

    71 vulnerabilities in third-party components as Node.js, cURL, SQLite, CivetWeb and DNS(ISC BIND) could allow an attacker to interfere with the affected product in various ways. Siemens has released an update for SINEC INS and recommends to update to the latest versions.

  • SSA-772220SSA-772220: OpenSSL Vulnerabilities in Industrial Products2021-07-13csaf · siemens_psirtDE

    OpenSSL has published a security advisory [0] about a vulnerability in OpenSSL versions 1.1.1 < 1.1.1k, that allows an unauthenticated attacker to cause a Denial-of-Service (DoS) if a maliciously crafted renegotiation message is sent. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends countermeasures for products where fixes are not, or not yet available. [0] https://www.openssl.org/news/secadv/20210325.txt

  • VDE-2021-025PHOENIX CONTACT: Security Advisory for PLCNext, ILC 2050 BI, FL MGUARD DM UNLIMITED, TC ROUTER und CLOUD CLIENT products2021-06-23csaf · phoenix_contact_psirtDE

    A Denial of Service and a CA Check Problem have been identified in multiple openSSL 1.1.1 versions, which are utilized in the Phoenix Contact products listed above.

  • WID-SEC-W-2022-0671OpenSSL: Mehrere SchwachstellenDeutsch2021-03-25csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in OpenSSL ausnutzen, um einen Denial of Service Angriff durchzuführen und um kryptografische Sicherheitsmechanismen zu umgehen.

  • WID-SEC-W-2023-0065Oracle MySQL: Mehrere SchwachstellenDeutsch2021-04-20csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Oracle MySQL ausnutzen, um die Verfügbarkeit, Vertraulichkeit und Integrität zu gefährden.

  • WID-SEC-W-2024-0794Dell ECS: Mehrere SchwachstellenDeutsch2024-04-04csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Dell ECS ausnutzen, um seine Privilegien zu erweitern, beliebigen Programmcode mit Administratorrechten auszuführen, Informationen offenzulegen, Dateien zu manipulieren, einen Cross-Site-Scripting-Angriff durchzuführen, Sicherheitsvorkehrungen zu umgehen oder einen Denial of Service Zustand herbeizuführen.

  • WID-SEC-W-2025-0227IBM QRadar SIEM: Mehrere SchwachstellenDeutsch2021-11-30csaf · cert_bundDE

    Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in IBM QRadar SIEM ausnutzen, um seine Privilegien zu erweitern, Administratorrechte zu erlangen, beliebigen Programmcode auszuführen, Informationen offenzulegen, Dateien zu manipulieren oder Sicherheitsvorkehrungen zu umgehen.

  • cisco-sa-openssl-2021-GHY28dJdMultiple Vulnerabilities in OpenSSL Affecting Cisco Products: March 20212021-03-25csaf · cisco_csafUS

    On March 25, 2021, the OpenSSL Project released a security advisory, OpenSSL Security Advisory [25 March 2021], ["https://www.openssl.org/news/secadv/20210325.txt"] that disclosed two vulnerabilities. Exploitation of these vulnerabilities could allow an attacker to use a valid non-certificate authority (CA) certificate to act as a CA and sign a certificate for an arbitrary organization, user or device, or to cause a denial of service (DoS) condition.

  • GHSA-83mx-573x-5rw9openssl-src NULL pointer Dereference in signature_algorithms processing2021-08-25ghsa · osvUS

    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).

  • ICSA-21-336-06Hitachi Energy APM Edge2021-12-02icsa · cisa_csaf_otUS

    Successful exploitation of this vulnerability could cause the product to become inaccessible.

  • ICSA-22-069-09Siemens SINEC INS2022-03-08icsa · cisa_csaf_otUS

    71 vulnerabilities in third-party components as Node.js, cURL, SQLite, CivetWeb and DNS(ISC BIND) could allow an attacker to interfere with the affected product in various ways. Siemens has released an update for SINEC INS and recommends to update to the latest versions.

  • ICSA-22-104-05Siemens OpenSSL Vulnerabilities in Industrial Products2021-07-13icsa · cisa_csaf_otUS

    OpenSSL has published a security advisory [0] about a vulnerability in OpenSSL versions 1.1.1 < 1.1.1k, that allows an unauthenticated attacker to cause a Denial-of-Service (DoS) if a maliciously crafted renegotiation message is sent. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends countermeasures for products where fixes are not, or not yet available. [0] https://www.openssl.org/news/secadv/20210325.txt

  • BIT-node-2021-3449NULL pointer deref in signature_algorithms processing2024-03-06vendor · osvUS

    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).

  • BIT-node-min-2021-3449NULL pointer deref in signature_algorithms processing2024-12-16vendor · osvUS

    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).

  • RUSTSEC-2021-0055NULL pointer deref in signature_algorithms processing2021-05-01vendor · osvUS

    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.

07

also known as (9)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundcisa_csaf_otcisco_csafsiemens_psirtphoenix_contact_psirtNVDCVE.orgMITRE
published 2021-03-25modified 2026-06-17
10

references (170)

External citations — patches, advisories, analysis.

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