Test ID:	1.3.6.1.4.1.25623.1.0.117062
Category:	Denial of Service
Title:	OpenSSL: EDIPARTYNAME NULL Pointer De-reference Vulnerability (CVE-2020-1971) (Windows)
Summary:	OpenSSL is prone to a Denial-of-Service (DoS) vulnerability.
Description:	Summary: OpenSSL is prone to a Denial-of-Service (DoS) vulnerability. Vulnerability Insight: The X.509 GeneralName type is a generic type for representing different types of names. One of those name types is known as EDIPartyName. OpenSSL provides a function GENERAL_NAME_cmp which compares different instances of a GENERAL_NAME to see if they are equal or not. This function behaves incorrectly when both GENERAL_NAMEs contain an EDIPARTYNAME. A NULL pointer dereference and a crash may occur leading to a possible denial of service attack. OpenSSL itself uses the GENERAL_NAME_cmp function for two purposes: 1) Comparing CRL distribution point names between an available CRL and a CRL distribution point embedded in an X509 certificate 2) When verifying that a timestamp response token signer matches the timestamp authority name (exposed via the API functions TS_RESP_verify_response and TS_RESP_verify_token) If an attacker can control both items being compared then that attacker could trigger a crash. For example if the attacker can trick a client or server into checking a malicious certificate against a malicious CRL then this may occur. Note that some applications automatically download CRLs based on a URL embedded in a certificate. This checking happens prior to the signatures on the certificate and CRL being verified. OpenSSL's s_server, s_client and verify tools have support for the '-crl_download' option which implements automatic CRL downloading and this attack has been demonstrated to work against those tools. Note that an unrelated bug means that affected versions of OpenSSL cannot parse or construct correct encodings of EDIPARTYNAME. However it is possible to construct a malformed EDIPARTYNAME that OpenSSL's parser will accept and hence trigger this attack. Vulnerability Impact: An attacker may trigger a crash and cause a DoS. Affected Software/OS: All OpenSSL 1.1.1 and 1.0.2 versions are affected by this issue. OpenSSL 1.1.0 is out of support and no longer receiving updates of any kind. The impact of this issue on OpenSSL 1.1.0 has not been analysed. Solution: OpenSSL 1.1.1 users should upgrade to 1.1.1i. OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2x. Other users should upgrade to OpenSSL 1.1.1i. CVSS Score: 4.3 CVSS Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P
Cross-Ref:	Common Vulnerability Exposure (CVE) ID: CVE-2020-1971 https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2154ab83e14ede338d2ede9bbe5cdfce5d5a6c9e https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=f960d81215ebf3f65e03d4d5d857fb9b666d6920 https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44676 https://security.netapp.com/advisory/ntap-20201218-0005/ https://security.netapp.com/advisory/ntap-20210513-0002/ https://www.openssl.org/news/secadv/20201208.txt https://www.tenable.com/security/tns-2020-11 https://www.tenable.com/security/tns-2021-09 https://www.tenable.com/security/tns-2021-10 Debian Security Information: DSA-4807 (Google Search) https://www.debian.org/security/2020/dsa-4807 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PWPSSZNZOBJU2YR6Z4TGHXKYW3YP5QG7/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DGSI34Y5LQ5RYXN4M2I5ZQT65LFVDOUU/ FreeBSD Security Advisory: FreeBSD-SA-20:33 https://security.FreeBSD.org/advisories/FreeBSD-SA-20:33.openssl.asc https://security.gentoo.org/glsa/202012-13 https://www.oracle.com//security-alerts/cpujul2021.html https://www.oracle.com/security-alerts/cpuApr2021.html https://www.oracle.com/security-alerts/cpujan2021.html https://lists.debian.org/debian-lts-announce/2020/12/msg00020.html https://lists.debian.org/debian-lts-announce/2020/12/msg00021.html http://www.openwall.com/lists/oss-security/2021/09/14/2 https://lists.apache.org/thread.html/rbb769f771711fb274e0a4acb1b5911c8aab544a6ac5e8c12d40c5143@%3Ccommits.pulsar.apache.org%3E https://lists.apache.org/thread.html/r63c6f2dd363d9b514d0a4bcf624580616a679898cc14c109a49b750c@%3Cdev.tomcat.apache.org%3E
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