CVE-2021-3449 Information

Description

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).

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=fb9fa6b51defd48157eeb207f52181f735d96148 https://www.openssl.org/news/secadv/20210325.txt https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-openssl-2021-GHY28dJd https://www.debian.org/security/2021/dsa-4875 https://security.netapp.com/advisory/ntap-20210326-0006/ https://security.FreeBSD.org/advisories/FreeBSD-SA-21:07.openssl.asc http://www.openwall.com/lists/oss-security/2021/03/27/1 http://www.openwall.com/lists/oss-security/2021/03/27/2 http://www.openwall.com/lists/oss-security/2021/03/28/3 http://www.openwall.com/lists/oss-security/2021/03/28/4 https://security.gentoo.org/glsa/202103-03 https://www.tenable.com/security/tns-2021-06 https://www.tenable.com/security/tns-2021-05 https://lists.fedoraproject.org/archives/list/[email protected]/message/CCBFLLVQVILIVGZMBJL3IXZGKWQISYNP/ https://kc.mcafee.com/corporate/index?page=content&id=SB10356 https://www.tenable.com/security/tns-2021-09 https://security.netapp.com/advisory/ntap-20210513-0002/ https://www.tenable.com/security/tns-2021-10 https://www.oracle.com/security-alerts/cpuApr2021.html https://cert-portal.siemens.com/productcert/pdf/ssa-772220.pdf https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44845 https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0013 https://www.oracle.com//security-alerts/cpujul2021.html https://lists.debian.org/debian-lts-announce/2021/08/msg00029.html https://www.oracle.com/security-alerts/cpuoct2021.html https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf https://www.oracle.com/security-alerts/cpuapr2022.html

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.9