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. All OpenSSL 1.1.1 and 1.0.2 versions are affected by this issue. Other OpenSSL releases are out of support and have not been checked. Fixed in OpenSSL 1.1.1i (Affected 1.1.1-1.1.1h). Fixed in OpenSSL 1.0.2x (Affected 1.0.2-1.0.2w).
References
Link Providers
http://www.openwall.com/lists/oss-security/2021/09/14/2 cve-icon cve-icon
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf cve-icon cve-icon
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=2154ab83e14ede338d2ede9bbe5cdfce5d5a6c9e cve-icon cve-icon
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=f960d81215ebf3f65e03d4d5d857fb9b666d6920 cve-icon cve-icon
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44676 cve-icon cve-icon
https://lists.apache.org/thread.html/r63c6f2dd363d9b514d0a4bcf624580616a679898cc14c109a49b750c%40%3Cdev.tomcat.apache.org%3E cve-icon cve-icon
https://lists.apache.org/thread.html/rbb769f771711fb274e0a4acb1b5911c8aab544a6ac5e8c12d40c5143%40%3Ccommits.pulsar.apache.org%3E cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2020/12/msg00020.html cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2020/12/msg00021.html cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DGSI34Y5LQ5RYXN4M2I5ZQT65LFVDOUU/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PWPSSZNZOBJU2YR6Z4TGHXKYW3YP5QG7/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2020-1971 cve-icon
https://security.FreeBSD.org/advisories/FreeBSD-SA-20:33.openssl.asc cve-icon cve-icon
https://security.gentoo.org/glsa/202012-13 cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20201218-0005/ cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20210513-0002/ cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20240621-0006/ cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2020-1971 cve-icon
https://www.debian.org/security/2020/dsa-4807 cve-icon cve-icon
https://www.openssl.org/news/secadv/20201208.txt cve-icon cve-icon cve-icon
https://www.oracle.com//security-alerts/cpujul2021.html cve-icon cve-icon
https://www.oracle.com/security-alerts/cpuApr2021.html cve-icon cve-icon
https://www.oracle.com/security-alerts/cpuapr2022.html cve-icon cve-icon
https://www.oracle.com/security-alerts/cpujan2021.html cve-icon cve-icon
https://www.oracle.com/security-alerts/cpuoct2021.html cve-icon cve-icon
https://www.tenable.com/security/tns-2020-11 cve-icon cve-icon
https://www.tenable.com/security/tns-2021-09 cve-icon cve-icon
https://www.tenable.com/security/tns-2021-10 cve-icon cve-icon
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: openssl

Published: 2020-12-08T15:30:16.835255Z

Updated: 2024-09-17T02:57:20.238Z

Reserved: 2019-12-03T00:00:00

Link: CVE-2020-1971

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2020-12-08T16:15:11.730

Modified: 2024-06-21T19:15:16.170

Link: CVE-2020-1971

cve-icon Redhat

Severity : Important

Publid Date: 2020-12-08T00:00:00Z

Links: CVE-2020-1971 - Bugzilla