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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.1056 OpenSSL security update 26 March 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: OpenSSL Publisher: OpenSSL Operating System: UNIX variants (UNIX, Linux, OSX) Windows Impact/Access: Denial of Service -- Unknown/Unspecified Access Confidential Data -- Unknown/Unspecified Provide Misleading Information -- Unknown/Unspecified Resolution: Patch/Upgrade CVE Names: CVE-2021-3450 CVE-2021-3449 Original Bulletin: https://www.openssl.org/news/secadv/20210325.txt Comment: This advisory references vulnerabilities in OpenSSL products which run on multiple platforms. It is recommended that administrators running OpenSSL check for an updated version of the software for their operating system. - --------------------------BEGIN INCLUDED TEXT-------------------- OpenSSL Security Advisory [25 March 2021] ========================================= CA certificate check bypass with X509_V_FLAG_X509_STRICT (CVE-2021-3450) ======================================================================== Severity: High The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a "purpose" has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named "purpose" values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer 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. This issue was reported to OpenSSL on 18th March 2021 by Benjamin Kaduk from Akamai and was discovered by Xiang Ding and others at Akamai. The fix was developed by Tomáš Mráz. NULL pointer deref in signature_algorithms processing (CVE-2021-3449) ===================================================================== Severity: High 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. This issue was reported to OpenSSL on 17th March 2021 by Nokia. The fix was developed by Peter Kästle and Samuel Sapalski from Nokia. Note ==== OpenSSL 1.0.2 is out of support and no longer receiving public updates. Extended support is available for premium support customers: https://www.openssl.org/support/contracts.html OpenSSL 1.1.0 is out of support and no longer receiving updates of any kind. The impact of these issues on OpenSSL 1.1.0 has not been analysed. Users of these versions should upgrade to OpenSSL 1.1.1. References ========== URL for this Security Advisory: https://www.openssl.org/news/secadv/20210325.txt Note: the online version of the advisory may be updated with additional details over time. For details of OpenSSL severity classifications please see: https://www.openssl.org/policies/secpolicy.html - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBYF0mTuNLKJtyKPYoAQhWTg//aoXOTqLJFcKRIQOaQsusNqXMiD9pBcZ+ Lj+H0tdtOnusacO2ZYW4BryB+GG8/6XkRkl5WmNwxNcFsD5QYrpuyePVc5ww6fBp taOE0WjxyKUAQhuqn7LLVM8aaEAO6Wm7wD5gBf0akssgqAQkHehPgFWIyqtH8Vzj StizYCBVR15I/N880cIFCV+v9UgF8nc1tvlR5IJWgjHzyPYV4dwIckhyKFheC9Es mt9ggjqCbuFqjYxBAQQfjoP9Q3IQWuty1N+F8lSpvY0ydRGEFjjOZcEb9fOdfnF3 /0I7AfL/leKiNKbcwaP1JYkP4aNlwRod/Kn4RhvW9ntRS7rIKm7I7g6+yduHd0Wn FZ1/LY6hHWc7hDlO1X2L2wh3uc8/NnxXtpCh7vcwvRotBRVw0y46Hhy1gFv2LDCD koDeF34/W8gCn84JinweJcuJpxI+Oqm6uhIn2o29HaCxLhN4Ld1UtrcmrIAYRzcL 84o3QcmjmeW31tXCcvjjnOPPplnAiC/oOvwv9v+dBGq1vpTX1AWxTtJxF+wOLaKK LCH7ZHg8FpKt2yUtQ5Lwkevk3jxS4qUXadbngEqpTkSJ1jUWyFrcNjLaaGv5FWny ya3x/heVXzWydx0gxLWvFFlmBdDEanWaq8b07r6Lo6VePUUDb8Q/fxiW3wUiAsAC 70DUHBNn6Sg= =Me5r -----END PGP SIGNATURE-----