CVE-2020-1971

Published: 08 December 2020

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).

Priority

High

CVSS 3 base score: 5.9

Status

Package Release Status
edk2
Launchpad, Ubuntu, Debian
Upstream Not vulnerable

Ubuntu 20.10 (Groovy Gorilla) Not vulnerable

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable

Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

nodejs
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Not vulnerable
(uses system openssl1.1)
Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(uses system openssl1.1)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(uses system openssl1.0)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(uses system openssl)
Ubuntu 14.04 ESM (Trusty Tahr) Not vulnerable
(uses system openssl)
openssl
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla)
Released (1.1.1f-1ubuntu4.1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (1.1.1f-1ubuntu2.1)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (1.1.1-1ubuntu2.1~18.04.7)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (1.0.2g-1ubuntu4.18)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (1.0.1f-1ubuntu2.27+esm2)
openssl1.0
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (1.0.2n-1ubuntu5.5)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist